Credit-substitution symbol mechanics with reel growth for random based game outcomes

ABSTRACT

A credit-substitution symbol mechanic for a gaming device is described. The credit-substitution symbol mechanic randomly triggers an add-substitution symbol feature in a game instance with an initial reel area and randomly determines an expanded reel size for a plurality of reels to be displayed in an expanded reel area. The credit-substitution symbol mechanic randomly determines a substitution symbol to be added to a first reel of the plurality of reels and randomly determines the substitution symbol is a credit-substitution symbol. The credit-substitution symbol mechanic determines that the credit-substitution symbol is part of a payline. The credit-substitution symbol mechanic performs a first payout for the payline that pays out a payline award and performs a second payout for the payline that pays out a credit value of the credit-substitution symbol.

RELATED APPLICATION

This application is related to co-filed U.S. patent application Ser. No.16/948,308, filed on Sep. 11, 2020, and titled “CREDIT-SUBSTITUTIONSYMBOL MECHANICS FOR RANDOM BASED GAME OUTCOMES,” which is herebyincorporated herein by referenced in its entirety.

BACKGROUND

The disclosure relates generally to the field of user interface (UI)design, electronic gaming devices, and electronic gaming software. Moreparticularly, but not by way of limitation, this disclosure relates toperforming gaming device operations that present and implement one ormore credit-substitution symbol mechanics for random based gameoutcomes.

Electronic gaming machines (EGMs) or gaming devices provide a variety ofwagering games such as slot games, video poker games, video blackjackgames, roulette games, video bingo games, keno games and other types ofgames that are frequently offered at casinos and other locations. Playon EGMs typically involves a player establishing a credit balance byinputting money, or another form of monetary credit, and placing amonetary wager (from the credit balance) on one or more outcomes of agame instance (or single play) of a primary or base game. In some cases,a player may qualify for a special mode of the base game, a secondarygame feature, or a bonus game feature of the base game by attaining acertain winning combination or triggering event in, or related to, thebase game, or after the player is randomly awarded the special mode,secondary game feature, or bonus game feature. In the special mode,secondary game feature, or bonus game feature, the player is given anopportunity to win extra game credits, game tokens or other forms ofpayout. In the case of “game credits” that are awarded during play, thegame credits are typically added to a credit meter total on the EGM andcan be provided to the player upon completion of a gaming session orwhen the player wants to “cash out.”

“Slot” type games are often displayed to the player in the form ofvarious symbols arrayed in a row-by-column grid or matrix. Specificmatching combinations of symbols along predetermined paths (or paylines)through the matrix indicate the outcome of the game. The displaytypically highlights winning combinations/outcomes for readyidentification by the player. Matching combinations and theircorresponding awards are usually shown in a “pay-table” which isavailable to the player for reference. Often, the player may varyhis/her wager to include differing numbers of paylines and/or the amountbet on each line. By varying the wager, the player may sometimes alterthe frequency or number of winning combinations, frequency or number ofsecondary game features, and/or the amount awarded.

Typical games use a random number generator (RNG) to randomly determinethe outcomes (also referenced throughout the disclosure as a “randombased game outcome”) for the games. Examples of random based gameoutcomes include slots, video poker, video blackjack, video pachinko,keno, bingo, and lottery outcomes. The games are also designed to returna certain percentage of the amount wagered back to the player over thecourse of many rounds of play or game instances, which is generallyreferred to as return to player (RTP) for a game. The RTP and randomnessof the RNG ensure the fairness of the games and are highly regulated.Upon initiation of play, the RNG randomly determines a game outcome andsymbols are then selected which correspond to that outcome. Notably,some games may include an element of skill on the part of the player andare therefore not entirely random.

EGMs often depend on usability (e.g., ease of use and playerunderstandability) and new or improved game features to enhance playerexperiences on the EGMs. Although previous EGMs include various UIfeatures, game features, and backend game processing operationsassociated with the UI features to improve usability and enhance playerexperiences, there is a continuous need for further improvement to EGMsand other electronic gaming devices, electronic gaming software, and/orUI design.

SUMMARY

In one implementation, a system comprises memory and a processoroperable to interact with the memory. The processor randomly triggers,based on a random number generator, an add-substitution symbol featureand randomly determines, based on the random number generator andtriggering the add-substitution symbol feature, a number of substitutionsymbols to add to a first reel to be displayed in a reel area. Theprocessor randomly determines, based on the random number generator, asubstitution symbol from the number of substitution symbols added to thefirst reel is a credit-substitution symbol and determines that thecredit-substitution symbol is part of a payline. The credit-substitutionsymbol substitutes as a different symbol type when forming the payline.The processor performs a first payout for the payline that pays out apayline award and performs a second payout for the payline that pays outa credit value of the credit-substitution symbol.

In another implementation, a system comprises memory and a processoroperable to interact with the memory. The processor presents triggeringan add-substitution symbol feature and presents a number of substitutionsymbols to add to a first reel to be displayed in a reel area. Theprocessor presents a substitution symbol from the number of substitutionsymbols added to the first reel is a credit-substitution symbol andpresents that the credit-substitution symbol is part of a payline. Thecredit-substitution symbol substitutes as a different symbol type whenforming the payline. The processor presents an animation of a firstpayout for the payline that pays out a payline award and a second payoutfor the payline that pays out a credit value of the credit-substitutionsymbol.

In another implementation, a method is described to implement acredit-substitution symbol mechanic. The method randomly triggers, basedon a random number generator, an add-substitution symbol feature andrandomly determines, based on the random number generator and triggeringthe add-substitution symbol feature, a number of substitution symbols toadd to a first reel to be displayed in a reel area. The method randomlydetermines, based on the random number generator, a substitution symbolfrom the number of substitution symbols added to the first reel is acredit-substitution symbol and determines that the credit-substitutionsymbol is part of a payline. The credit-substitution symbol substitutesas a different symbol type when forming the payline. The method performsa first payout for the payline that pays out a payline award andperforms a second payout for the payline that pays out a credit value ofthe credit-substitution symbol.

In another implementation, a method is described to implement acredit-substitution symbol mechanic. The method presents triggering anadd-substitution symbol feature and presents a number of substitutionsymbols to add to a first reel to be displayed in a reel area. Themethod presents a substitution symbol from the number of substitutionsymbols added to the first reel is a credit-substitution symbol andpresents that the credit-substitution symbol is part of a payline. Thecredit-substitution symbol substitutes as a different symbol type whenforming the payline. The method presents an animation of a first payoutfor the payline that pays out a payline award and a second payout forthe payline that pays out a credit value of the credit-substitutionsymbol.

In another implementation, a system comprises memory and a processoroperable to interact with the memory. The processor randomly triggers,based on a random number generator, an add-substitution symbol featurein a game instance with an initial reel area and randomly determines,based on the random number generator and triggering the add-substitutionsymbol feature, an expanded reel size for a plurality of reels to bedisplayed in an expanded reel area, wherein the expanded reel area islarger than the initial reel rea. The processor randomly determines,based on the random number generator and triggering the add-substitutionsymbol feature, a substitution symbol to be added to a first reel of theplurality of reels and randomly determines, based on the random numbergenerator, the substitution symbol is a credit-substitution symbol. Theprocessor determines that the credit-substitution symbol is part of apayline, where the credit-substitution symbol substitutes as a differentsymbol type when forming the payline. The processor performs a firstpayout for the payline that pays out a payline award and performs asecond payout for the payline that pays out a credit value of thecredit-substitution symbol.

In another implementation, a system comprises memory and a processoroperable to interact with the memory. The processor presents triggeringan add-substitution symbol feature in a game instance with an initialreel area and an expanded reel size for a plurality of reels to bedisplayed in an expanded reel area, where the expanded reel area islarger than the initial reel rea. The processor presents a substitutionsymbol to be added to a first reel of the plurality of reels andpresents that the substitution symbol is a credit-substitution symbol.The processor presents that the credit-substitution symbol is part of apayline, where the credit-substitution symbol substitutes as a differentsymbol type when forming the payline. The processor presents a firstpayout for the payline that pays out a payline award and presents asecond payout for the payline that pays out a credit value of thecredit-substitution symbol.

In another implementation, a method is described to implement acredit-substitution symbol mechanic. The method randomly triggers, basedon a random number generator, an add-substitution symbol feature in agame instance with an initial reel area and randomly determines, basedon the random number generator and triggering the add-substitutionsymbol feature, an expanded reel size for a plurality of reels to bedisplayed in an expanded reel area, wherein the expanded reel area islarger than the initial reel rea. The method randomly determines, basedon the random number generator and triggering the add-substitutionsymbol feature, a substitution symbol to be added to a first reel of theplurality of reels and randomly determines, based on the random numbergenerator, the substitution symbol is a credit-substitution symbol. Themethod determines that the credit-substitution symbol is part of apayline, where the credit-substitution symbol substitutes as a differentsymbol type when forming the payline. The method performs a first payoutfor the payline that pays out a payline award and performs a secondpayout for the payline that pays out a credit value of thecredit-substitution symbol.

In another implementation, a method is described to implement acredit-substitution symbol mechanic. The method presents triggering anadd-substitution symbol feature in a game instance with an initial reelarea and an expanded reel size for a plurality of reels to be displayedin an expanded reel area, where the expanded reel area is larger thanthe initial reel rea. The method presents a substitution symbol to beadded to a first reel of the plurality of reels and presents that thesubstitution symbol is a credit-substitution symbol. The method presentsthat the credit-substitution symbol is part of a payline, where thecredit-substitution symbol substitutes as a different symbol type whenforming the payline. The method presents a first payout for the paylinethat pays out a payline award and presents a second payout for thepayline that pays out a credit value of the credit-substitution symbol.

In one or more implementations, each of the above described methods, andvariations thereof, may be implemented as a series of computerexecutable instructions executed on a programmable electronic device.Such instructions may use any one or more convenient programminglanguage. Such instructions may be collected into engines and/orprograms and stored in any computer-readable medium or media that isreadable and executable by a computer system, gaming device, or otherprogrammable electronic device.

BRIEF DESCRIPTION OF THE DRAWINGS

While certain implementations will be described in connection with theillustrative implementations shown herein, this disclosure is notlimited to those implementations. On the contrary, all alternatives,modifications, and equivalents are included within the spirting andscope of the invention as defined by the claims. In the drawings, whichare not to scale, the same reference numerals are used throughout thedescription and in the drawing figures for components and elementshaving the same structure. If applicable, primed reference numerals areused for components and elements having similar function andconstruction to those components and elements having the same unprimedreference numerals.

FIG. 1 is an exemplary diagram showing several EGMs networked withvarious gaming related servers.

FIG. 2A is a block diagram showing various functional elements of anexemplary EGM.

FIG. 2B depicts a casino gaming environment according to one example.

FIG. 2C is a diagram that shows examples of components of a system forproviding online gaming according to some aspects of the presentdisclosure.

FIG. 3 illustrates, in block diagram form, an implementation of a gameprocessing architecture that implements a game processing pipeline forthe play of a game in accordance with various implementations describedherein.

FIG. 4 is a diagram that depicts example general layouts of UIs relatedto presenting an add-substitution symbol supplemental feature that addssubstitution symbols when the reels are spinning.

FIG. 5 is a diagram that depicts example general layouts of UIs relatedto presenting an add-substitution symbol supplemental feature that addssubstitution symbols after the reels have stopped.

FIG. 6 is a diagram that depicts example general layouts of UIs relatedto presenting a re-spin feature that adds extra substitution symbols toreels after completing the add-substitution symbol supplemental feature.

FIG. 7 is an example screenshot of a bonus game play UI that correspondsto a themed version of a bonus game play UI shown in FIG. 4 .

FIG. 8 is an example screenshot of a bonus game play UI that correspondsto a themed version of bonus game play UIs shown in FIGS. 4-6 .

FIG. 9 depicts a flowchart illustrating a UI based operation forpresenting a add-substitution symbol supplemental feature triggered froma base game and/or supplement game feature.

FIG. 10 depicts a flowchart illustrating backend-based operation forimplementing one or more credit-substitution symbol mechanics.

FIG. 11 is a diagram that depicts example general layouts of UIs relatedto presenting an add-substitution symbol supplemental feature thatexpands the reel size and adds substitution symbols to the expanded reelarea.

FIG. 12 is a diagram that depicts example general layouts of UIs relatedto presenting an add-substitution symbol supplemental feature thatpresents multiple paylines.

FIG. 13 is a diagram that depicts example general layouts of UIs relatedto presenting an add-substitution symbol supplemental feature overmultiple game instances.

FIG. 14 is an example screenshot of a bonus game play UI thatcorresponds to a themed version of bonus game play UI shown in FIG. 11 .

FIG. 15 is an example screenshot of a bonus game play UI thatcorresponds to a themed version of bonus game play UIs shown in FIG. 12.

FIG. 16 depicts a flowchart illustrating a UI based operation forpresenting a add-substitution symbol supplemental feature triggered froma base game and/or supplement game feature.

FIG. 17 depicts a flowchart illustrating backend-based operation forimplementing one or more credit-substitution symbol mechanics over oneor more game instances.

DETAILED DESCRIPTION

The disclosure includes various example implementations that generaterandom based game outcomes according to one or more credit-substitutionsymbol mechanics. In one or more implementations, a gaming devicegenerates one or more credit-wild symbols (also referenced throughoutthis disclosure as “credit-substitution symbols”) in one or moreadd-substitution symbol supplemental features (e.g., a special mode,secondary game, or bonus game). In a base game and/or supplemental gamefeature (e.g., a free games bonus feature), the gaming device randomlydetermines whether to trigger the add-substitution symbol supplementalfeature. After entering the add-substitution symbol supplementalfeature, the gaming device adds wild symbols (also referenced throughoutthis disclosure as “substitution symbols”) to a displayed reel area witha given reel configuration, such as a 5×4 reel configuration. Thedisplayed reel area for the add-substitution symbol supplemental featurehas the same reel configuration and reel size as the base game and/orsupplemental game feature. Stated another way, the add-substitutionsymbol supplemental feature does not include a reel growth operation.

When adding wild symbols, the gaming device performs a randomsubstitution determination operation that randomly adds plain-wildsymbols (also generally referred throughout this disclosure as“plain-substitution symbols”) and/or credit-wild symbols (also generallyreferred throughout this disclosure as “credit-substitution symbols”) tothe displayed reel area. To perform the random substitutiondetermination operation, the gaming device determines the number of wildsymbols that land on each reel in the displayed reel area. The gamingdevice also randomly determines which set of substitution volatilitylookup tables to use when determining whether to add plain-wild symbols.For example, the gaming device can have two sets of substitutionvolatility lookup tables. One set is configured to generate credit-wildsymbols at a relatively lower rate than a second set of substitutionvolatility lookup tables. Each set of substitution volatility lookuptables includes a separate substitution volatility lookup table for eachreel displayed in the reel area. After randomly selecting one set ofsubstitution volatility lookup tables and determining the number of wildsymbols to add to each reel, the gaming device uses the appropriatesubstitution volatility lookup table to randomly determine whether eachadded wild symbol for a given reel should be plain-wild symbol orcredit-wild symbol. For each credit-wild symbol added to the displayedreel area, the gaming device randomly determines the credit values usinga credit volatility lookup table associated with a given reel. Thegaming device could also use a separate credit volatility lookup tablefor each reel shown in the displayed reel area. Any win line thatcontains a credit-wild symbol will pay the amount shown on thecredit-wild symbol in addition to the payline award.

Additionally, or alternatively, the gaming device can perform acredit-substitution symbol mechanic that includes a reel growthoperation in one or more add-substitution symbol supplemental features.In one or more implementations, an add-substitution symbol supplementalfeature could be a single spin with a reel growth operation. Afterentering the add-substitution symbol supplemental feature, the gamingdevice randomly adds wild symbols to a displayed reel area that randomlyexpands its reel size. For example, the displayed reel area couldinitially have a 5×4 reel configuration in a base game. When performingthe spin in the supplemental game feature, the reel configuration couldvertically expand to a 5×10 reel configuration. To account for a targetgame RTP and the reel growth operation, the gaming device performs areel growth, substitution determination operation that randomly addsplain-wild symbols and/or credit-wild symbols to certain reels in thedisplayed reel area. As an example, the gaming device could potentiallyadd plain-wild symbols to all reels in the displayed reel area andcredit-wild symbols to a designated subset of the reels, such as reelspositioned in columns 3-5 of the displayed reel area.

To implement a reel growth, substitution determination operation, thegaming device accounts for adding wild symbols to the expanded portionof the reel area. To perform the reel growth, substitution determinationoperation, the reel growth, substitution determination operationrandomly determines the reel size (e.g., up to 14 rows added to the reelarea) and whether to add plain-wild symbols or credit-wild symbols to agiven reel. The gaming device could also have a designated minimumnumber of reels that will have at least one wild symbol added to thereels (e.g., two reels with at least one wild symbol added). Afterdetermining the reel size and whether plain-wild symbols or credit-wildsymbols are added to a given reel, the gaming device determines whichsymbol window positions to add wild symbols for the given reel. If thegaming device determines that credit-wild symbols will be added to oneor more reels, the gaming device utilizes one or more credit volatilitylookup tables that dynamically determine the range of the credit valuesassigned for credit symbols (e.g., low, medium, or high game creditvalues). In one or more implementations, the gaming device can also havea designated minimum number of wild symbols that should be added to agiven reel (e.g., two wild symbols per reel) based on the reel size. Forexample, the designated minimum number of wild symbols could be set toadd two wild symbols to each reel when the reel area grows to a 5×7 reelconfiguration. In comparison, if the reel area grows to a 5×14 reelconfiguration, the designated minimum number of wild symbols could beset to add four wild symbols to each reel.

In one or more implementations, the add-substitution symbol supplementalfeature can add wild symbols to a displayed reel area that grows overmultiple spins. For example, the add-substitution symbol supplementalfeature can be incorporated into a supplemental game feature, such as afree games bonus feature. To implement a reel growth, substitutiondetermination operation in the supplemental game feature, the gamingdevice adds wild symbols to a reel area that randomly grows overmultiple spins. The gaming device can randomly determine which spins ina set of initial spins will add wild symbols and the reel size for eachspin. For the spins that will add wild symbols, the gaming devicerandomly determines whether to add plain-wild symbols or credit-wildsymbols to a given reel based on the designated minimum number of reelsthat will have at least one wild symbol added. The gaming device willalso randomly and separately determine the reel size for each spin.After determining the reel size and whether plain-wild symbols orcredit-wild symbols are added to a given reel, the gaming devicerandomly determines which symbol window positions to add wild symbolsfor the given reel.

In terms of technical effects, the credit-substitution symbol mechanicsdescribed throughout the disclosure delivers improvements to electronicgaming software, UI design, and/or gaming devices by providing newand/or improved gaming device operations that comply with gamingregulations. For example, the use of credit-substitution symbolmechanics provides multiple payout operations when a credit-wild symbolis part of a payline. Specifically, the gaming device performs onepayout operation for the payline award and another payout operation forthe credit value of the credit-wild symbol. In contrast, otherimplementations that include a plain-wild symbol generally perform asingle payout operation that credits the payline award to a player. Thenumber of payout operations that pays out the credit value of thecredit-wild symbol depends on the number of paylines that credit-wildsymbol is part of. As an example, if a credit-wild symbol is part offour different paylines, the credit value of the credit-wild symbol ispaid out four times. Performing multiple payout operations for acredit-wild symbol, enlarging a reel area, and randomly addingcredit-wild symbols to a reel area are operations that increase gamevolatility through increasing the payout potential earned from a singlespin or over multiple spins. The disclosed credit-wild symbol mechanics,thus, increase game volatility while ensuring game randomness, a targetgame RTP (e.g., an overall game RTP of 90%), and compliance with otherregulatory constraints. These and other technical features are describedin greater detail later in the disclosure.

Example Electronic Gaming Devices and Gaming Environments

FIG. 1 illustrates several different models of EGMs that could bespecially configured to generate random based game outcomes using one ormore symbol frame mechanic. As shown in FIG. 1 , the EGMs, which aremore generally referred to as gaming devices 104A-104X, may be networkedto various gaming related servers. Shown is a system 100 in a gamingenvironment including one or more server computers 102 (e.g., slotservers of a casino) that are in communication, via a communicationsnetwork, with one or more gaming devices 104A-104X (e.g., EGMs, slots,video poker, bingo machines, etc.) that can implement one or moreaspects of the present disclosure. The gaming devices 104A-104X mayalternatively be portable and/or remote gaming devices such as, but notlimited to, a smart phone, a tablet, a laptop, or a game console. Gamingdevices 104A-104X utilize specialized software and/or hardware to formnon-generic, particular machines or apparatuses that comply withregulatory requirements regarding devices used for wagering or games ofchance that provide monetary awards.

Communication between the gaming devices 104A-104X and the servercomputers 102, and among the gaming devices 104A-104X, may be direct orindirect using one or more communication protocols. As an example,gaming devices 104A-104X and the server computers 102 can communicateover one or more communication networks, such as over the Internetthrough a website maintained by a computer on a remote server or over anonline data network including commercial online service providers,Internet service providers, private networks (e.g., local area networksand enterprise networks), and the like (e.g., wide area networks). Thecommunication networks could allow gaming devices 104A-104X tocommunicate with one another and/or the server computers 102 using avariety of communication-based technologies, such as radio frequency(RF) (e.g., wireless fidelity (WiFi®) and Bluetooth®), cable TV,satellite links and the like.

In some implementation, server computers 102 may not be necessary and/orpreferred. For example, in one or more implementations, a stand-alonegaming device such as gaming device 104A, gaming device 104B or any ofthe other gaming devices 104C-104X can implement one or more aspects ofthe present disclosure. However, it is typical to find multiple EGMsconnected to networks implemented with one or more of the differentserver computers 102 described herein.

The server computers 102 may include a central determination gamingsystem server 106, a ticket-in-ticket-out (TITO) system server 108, aplayer tracking system server 110, a progressive system server 112,and/or a casino management system server 114. Gaming devices 104A-104Xmay include features to enable operation of any or all servers for useby the player and/or operator (e.g., the casino, resort, gamingestablishment, tavern, pub, etc.). For example, game outcomes may begenerated on a central determination gaming system server 106 and thentransmitted over the network to any of a group of remote terminals orremote gaming devices 104A-104X that utilize the game outcomes anddisplay the results to the players.

Gaming device 104A is often of a cabinet construction which may bealigned in rows or banks of similar devices for placement and operationon a casino floor. The gaming device 104A often includes a main doorwhich provides access to the interior of the cabinet. Gaming device 104Atypically includes a button area or button deck 120 accessible by aplayer that is configured with input switches or buttons 122, an accesschannel for a bill validator 124, and/or an access channel for aticket-out printer 126.

In FIG. 1 , gaming device 104A is shown as a Relm XL™ model gamingdevice manufactured by Aristocrat® Technologies, Inc. As shown, gamingdevice 104A is a reel machine having a gaming display area 118comprising a number (typically 3 or 5) of mechanical reels 130 withvarious symbols displayed on them. The mechanical reels 130 areindependently spun and stopped to show a set of symbols within thegaming display area 118 which may be used to determine an outcome to thegame.

In many configurations, the gaming device 104A may have a main display128 (e.g., video display monitor) mounted to, or above, the gamingdisplay area 118. The main display 128 can be a high-resolution liquidcrystal display (LCD), plasma, light emitting diode (LED), or organiclight emitting diode (OLED) panel which may be flat or curved as shown,a cathode ray tube, or other conventional electronically controlledvideo monitor.

In some implementations, the bill validator 124 may also function as a“ticket-in” reader that allows the player to use a casino issued creditticket to load credits onto the gaming device 104A (e.g., in a cashlessTITO system). In such cashless implementations, the gaming device 104Amay also include a “ticket-out” printer 126 for outputting a creditticket when a “cash out” button is pressed. Cashless TITO systems areused to generate and track unique bar-codes or other indicators printedon tickets to allow players to avoid the use of bills and coins byloading credits using a ticket reader and cashing out credits using aticket-out printer 126 on the gaming device 104A. The gaming device 104Acan have hardware meters for purposes including ensuring regulatorycompliance and monitoring the player credit balance. In addition, therecan be additional meters that record the total amount of money wageredon the gaming device, total amount of money deposited, total amount ofmoney withdrawn, total amount of winnings on gaming device 104A.

In some implementations, a player tracking card reader 144, atransceiver for wireless communication with a mobile device (e.g., aplayer's smartphone), a keypad 146, and/or an illuminated display 148for reading, receiving, entering, and/or displaying player trackinginformation is provided in gaming device 104A. In such implementations,a game controller within the gaming device 104A can communicate with theplayer tracking system server 110 to send and receive player trackinginformation.

Gaming device 104A may also include a bonus topper wheel 134. When bonusplay is triggered (e.g., by a player achieving a particular outcome orset of outcomes in the primary game), bonus topper wheel 134 isoperative to spin and stop with indicator arrow 136 indicating theoutcome of the bonus game feature. Bonus topper wheel 134 is typicallyused to play a bonus game feature, but it could also be incorporatedinto play of the base or primary game.

A candle 138 may be mounted on the top of gaming device 104A and may beactivated by a player (e.g., using a switch or one of buttons 122) toindicate to operations staff that gaming device 104A has experienced amalfunction or the player requires service. The candle 138 is also oftenused to indicate a jackpot has been won and to alert staff that a handpayout of an award may be needed.

There may also be one or more information panels 152 which may be aback-lit, silkscreened glass panel with lettering to indicate generalgame information including, for example, a game denomination (e.g.,$0.01 or $0.05), paylines, pay tables, and/or various game relatedgraphics. In some implementations, the information panel(s) 152 may beimplemented as an additional video display.

Gaming devices 104A have traditionally also included a handle 132typically mounted to the side of main cabinet 116 which may be used toinitiate game play. Many or all the above described components can becontrolled by circuitry (e.g., a game controller) housed inside the maincabinet 116 of the gaming device 104A, the details of which are shown inFIG. 2A.

An alternative example gaming device 104B illustrated in FIG. 1 is theArc™ model gaming device manufactured by Aristocrat® Technologies, Inc.Note that where possible, reference numerals identifying similarfeatures of the gaming device 104A implementation are also identified inthe gaming device 104B implementation using the same reference numbers.Gaming device 104B does not include physical reels and instead showsgame play functions on main display 128. An optional topper screen 140may be used as a secondary game feature display for bonus play, to showgame features or attraction activities while a game is not in play, orany other information or media desired by the game designer or operator.In some implementations, the optional topper screen 140 may also oralternatively be used to display progressive jackpots available to aplayer during play of gaming device 104B.

Example gaming device 104B includes a main cabinet 116 including a maindoor which opens to provide access to the interior of the gaming device104B. The main or service door is typically used by service personnel torefill the ticket-out printer 126 and collect bills and tickets insertedinto the bill validator 124. The main or service door may also beaccessed to reset the machine, verify, and/or upgrade the software, andfor general maintenance operations.

Another example gaming device 104C shown is the Helix™ model gamingdevice manufactured by Aristocrat® Technologies, Inc. Gaming device 104Cincludes a main display 128A that is in a landscape orientation.Although not illustrated by the front view provided, the main display128A may have a curvature radius from top to bottom, or alternativelyfrom side to side. In some implementations, main display 128A is a flatpanel display. Main display 128A is typically used for primary game playwhile secondary display 128B is typically used for bonus game play, toshow game features or attraction activities while the game is not inplay or any other information or media desired by the game designer oroperator. In some implementations, example gaming device 104C may alsoinclude speakers 142 to output various audio such as game sound,background music, etc.

Many different types of games, including mechanical slot games, videoslot games, video poker, video black jack, video pachinko, keno, bingo,and lottery, may be provided with or implemented within the depictedgaming devices 104A-104C and other similar gaming devices. Each gamingdevice may also be operable to provide many different games. Games maybe differentiated according to themes, sounds, graphics, type of game(e.g., slot game vs. card game vs. game with aspects of skill),denomination, number of paylines, maximum jackpot, progressive ornon-progressive, bonus game features, and may be deployed for operationin Class 2 or Class 3, etc.

FIG. 2A is a block diagram depicting exemplary internal electroniccomponents of a gaming device 200 connected to various external systems.All or parts of the gaming device 200 shown could be used to implementany one of the example gaming devices 104A-X depicted in FIG. 1 .Similar to FIG. 1 , gaming device 200 can be specially configured togenerate random based game outcomes using a repeat accrual metermechanic. As shown in FIG. 2A, gaming device 200 includes a topperdisplay 216 or another form of a top box (e.g., a topper wheel, a topperscreen, etc.) that sits above cabinet 218. Cabinet 218 or topper display216 may also house a number of other components which may be used to addfeatures to a game being played on gaming device 200, including speakers220, a ticket printer 222 which prints bar-coded tickets or other mediaor mechanisms for storing or indicating a player's credit value, aticket reader 224 which reads bar-coded tickets or other media ormechanisms for storing or indicating a player's credit value, and aplayer tracking interface 232. Player tracking interface 232 may includea keypad 226 for entering information, a player tracking display 228 fordisplaying information (e.g., an illuminated or video display), a cardreader 230 for receiving data and/or communicating information to andfrom media or a device such as a smart phone enabling player tracking.FIG. 2A also depicts utilizing a ticket printer 222 to print tickets fora TITO system server 108. Gaming device 200 may further include a billvalidator 234, player-input buttons 236 for player input, cabinetsecurity sensors 238 to detect unauthorized opening of the cabinet 218,a primary game display 240, and a secondary game display 242, eachcoupled to and operable under the control of game controller 202.

The games available for play on the gaming device 200 are controlled bya game controller 202 that includes one or more processors 204.Processor 204 represents a general-purpose processor, a specializedprocessor intended to perform certain functional tasks, or a combinationthereof. As an example, processor 204 can be a central processing unit(CPU) that has one or more multi-core processing units and memorymediums (e.g., cache memory) that function as buffers and/or temporarystorage for data. Alternatively, processor 204 can be a specializedprocessor, such as an application specific integrated circuit (ASIC),graphics processing unit (GPU), field-programmable gate array (FPGA),digital signal processor (DSP), or another type of hardware accelerator.In another example, processor 204 is a system on chip (SoC) thatcombines and integrates one or more general-purpose processors and/orone or more specialized processors. Although FIG. 2A illustrates thatgame controller 202 includes a single processor 204, game controller 202is not limited to this representation and instead can include multipleprocessors 204 (e.g., two or more processors).

FIG. 2A illustrates that processor 204 is operatively coupled to memory208. Memory 208 is defined herein as including volatile and nonvolatilememory and other types of non-transitory data storage components.Volatile memory is memory that does not retain data values upon loss ofpower. Nonvolatile memory is memory that does retain data upon a loss ofpower. Examples of memory 208 include random access memory (RAM),read-only memory (ROM), hard disk drives, solid-state drives, universalserial bus (USB) flash drives, memory cards (e.g., Compact Fast (CFast)memory card), floppy disks accessed via an associated floppy disk drive,optical discs accessed via an optical disc drive, magnetic tapesaccessed via an appropriate tape drive, and/or other memory components,or a combination of any two or more of these memory components. Inaddition, examples of RAM include static random access memory (SRAM),dynamic random access memory (DRAM), magnetic random access memory(MRAM), and other such devices. Examples of ROM include a programmableread-only memory (PROM), an erasable programmable read-only memory(EPROM), an electrically erasable programmable read-only memory(EEPROM), or other like memory device. Even though FIG. 2A illustratesthat game controller 202 includes a single memory 208, game controller202 could include multiple memories 208 for storing program instructionsand/or data.

Memory 208 can store one or more game programs 206 that provide programinstructions and/or data for carrying out various implementations (e.g.,game mechanics) described herein. Stated another way, game program 206represents an executable program stored in any portion or component ofmemory 208. In one or more implementations, game program 206 is embodiedin the form of source code that includes human-readable statementswritten in a programming language or machine code that containsnumerical instructions recognizable by a suitable execution system, suchas a processor 204 in a game controller or other system. Examples ofexecutable programs include: (1) a compiled program that can betranslated into machine code in a format that can be loaded into arandom access portion of memory 208 and run by processor 204; (2) sourcecode that may be expressed in proper format such as object code that iscapable of being loaded into a random access portion of memory 208 andexecuted by processor 204; and (3) source code that may be interpretedby another executable program to generate instructions in a randomaccess portion of memory 208 to be executed by processor 204.

Alternatively, game programs 206 can be set up to generate one or moregame instances based on instructions and/or data that gaming device 200exchanges with one or more remote gaming devices, such as a centraldetermination gaming system server 106 (not shown in FIG. 2A but shownin FIG. 1 ). For purpose of this disclosure, the term “game instance”refers to a play or a round of a game that gaming device 200 presents(e.g., via UI) to a player. The game instance is communicated to gamingdevice 200 via the network 214 and then displayed on gaming device 200.For example, gaming device 200 may execute game program 206 as videostreaming software that allows the game to be displayed on gaming device200. When a game is stored on gaming device 200, it may be loaded frommemory 208 (e.g., from a read only memory (ROM)) or from the centraldetermination gaming system server 106 to memory 208.

Gaming devices, such as gaming device 200, are highly regulated toensure fairness and, in many cases, gaming device 200 is operable toaward monetary awards (e.g., typically dispensed in the form of aredeemable voucher). Therefore, to satisfy security and regulatoryrequirements in a gaming environment, hardware and softwarearchitectures are implemented in gaming devices 200 that differsignificantly from those of general-purpose computers. Adapting generalpurpose computers to function as gaming devices 200 is not simple orstraightforward because of: (1) the regulatory requirements for gamingdevices 200, (2) the harsh environment in which gaming devices 200operate, (3) security requirements, (4) fault tolerance requirements,and (5) the requirement for additional special purpose componentryenabling functionality of an EGM. These differences require substantialengineering effort with respect to game design implementation, gamemechanics, hardware components, and software.

One regulatory requirement for games running on gaming device 200generally involves complying with a certain level of randomness.Typically, gaming jurisdictions mandate that gaming devices 200 satisfya minimum level of randomness without specifying how a gaming device 200should achieve this level of randomness. To comply, FIG. 2A illustratesthat gaming device 200 could include an RNG 212 that utilizes hardwareand/or software to generate RNG outcomes that lack any pattern. The RNGoperations are often specialized and non-generic in order to comply withregulatory and gaming requirements. For example, in a slot game, gameprogram 206 can initiate multiple RNG calls to RNG 212 to generate RNGoutcomes, where each RNG call and RNG outcome corresponds to an outcomefor a reel. In another example, gaming device 200 can be a Class IIgaming device where RNG 212 generates RNG outcomes for creating Bingocards. In one or more implementations, RNG 212 could be one of a set ofRNGs operating on gaming device 200. More generally, an output of theRNG 212 can be the basis on which game outcomes are determined by thegame controller 202. Game developers could vary the degree of truerandomness for each RNG (e.g., pseudorandom) and utilize specific RNGsdepending on game requirements. The output of the RNG 212 can include arandom number or pseudorandom number (either is generally referredthroughout this disclosure as a “random number”).

In FIG. 2A, RNG 212 and hardware RNG 244 are shown in dashed lines toillustrate that RNG 212, hardware RNG 244, or both can be included ingaming device 200. In one implementation, instead of including RNG 212,gaming device 200 could include a hardware RNG 244 that generates RNGoutcomes. Analogous to RNG 212, hardware RNG 244 performs specializedand non-generic operations in order to comply with regulatory and gamingrequirements. For example, because of regulation requirements, hardwareRNG 244 could be a random number generator that securely produces randomnumbers for cryptography use. The gaming device 200 then uses the securerandom numbers to generate game outcomes for one or more game features(e.g., bonus game feature, special mode, secondary game feature, and/orother supplemental game features). In another implementation, the gamingdevice 200 could include both hardware RNG 244 and RNG 212. RNG 212 mayutilize the RNG outcomes from hardware RNG 244 as one of many sources ofentropy for generating secure random numbers for the game features.

Another regulatory requirement for running games on gaming device 200includes ensuring a certain level of RTP. Similar to the randomnessrequirement discussed above, numerous gaming jurisdictions also mandatethat gaming device 200 provides a predetermined level of RTP (e.g., RTPof at least 75%) for a game (also referenced throughout the disclosureas a “target game RTP”). A game can use one or more lookup tables (alsoreferenced throughout this disclosure as “weighted tables”) as part of atechnical solution that satisfies regulatory requirements for randomnessand RTP. In particular, a lookup table can integrate game features(e.g., trigger events for special modes or bonus game features; newlyintroduced game elements such as extra reels, new symbols, or new cards;stop positions for dynamic game elements such as spinning reels,spinning wheels, or shifting reels; or card selections from a deck) withrandom numbers generated by one or more RNGs, so as to achieve a givenlevel of volatility for a target game RTP. In general, volatility refersto the frequency or probability of an event such as a special mode,payout, etc. For example, to achieve a specific target game RTP, ahigher-volatility game may have a lower payout most of the time with anoccasional bonus having a very high payout, while a lower-volatilitygame has a steadier payout with more frequent bonuses of smalleramounts. Configuring a lookup table can involve engineering decisionswith respect to how RNG outcomes are mapped to game outcomes for a givengame feature, while still satisfying regulatory requirements for RTP.Configuring a lookup table can also involve engineering decisions aboutwhether different game features are combined in a given entry of thelookup table or split between different entries (for the respective gamefeatures), while still satisfying regulatory requirements for RTP andallowing for varying levels of game volatility.

FIG. 2A illustrates that gaming device 200 includes an RNG conversionengine 210 that translates the RNG outcome from RNG 212 to a gameoutcome presented to a player. To meet a designated RTP, a gamedeveloper can set up the RNG conversion engine 210 to utilize one ormore lookup tables and/or reel strips to translate the RNG outcome to asymbol element, stop position for a reel strip, and/or randomly chosenaspect of a game feature. As an example, the lookup tables can regulatea prize payout amount for each RNG outcome and how often the gamingdevice 200 pays out the prize payout amounts. The RNG conversion engine210 could utilize one lookup table and/or reel strips to map the RNGoutcome to a game outcome displayed to a player and a second lookuptable as a pay table for determining the prize payout amount for eachgame outcome. The mapping between the RNG outcome to the game outcomecontrols the frequency in hitting certain prize payout amounts.

FIG. 2A also depicts that gaming device 200 is connected over network214 to player tracking system server 110. Player tracking system server110 may be, for example, an OASIS® system manufactured by Aristocrat®Technologies, Inc. Player tracking system server 110 is used to trackplay (e.g., amount wagered, games played, time of play and/or otherquantitative or qualitative measures) for individual players so that anoperator may reward players in a loyalty program. The player may use theplayer tracking interface 232 to access his/her account information,activate free play, and/or request various information. Player trackingor loyalty programs seek to reward players for their play and help buildbrand loyalty to the gaming establishment. The rewards typicallycorrespond to the player's level of patronage (e.g., to the player'splaying frequency and/or total amount of game plays at a given casino).Player tracking rewards may be complimentary and/or discounted meals,lodging, entertainment, and/or additional play. Player trackinginformation may be combined with other information that is now readilyobtainable by a casino management system.

When a player wishes to play the gaming device 200, he/she can insertcash or a ticket voucher through a coin acceptor (not shown) or billvalidator 234 to establish a credit balance on the gaming device. Thecredit balance is used by the player to place wagers on instances of thegame and to receive game credit awards based on the outcome of winninginstances. The credit balance is decreased by the amount of each wagerand increased upon a win. The player can add additional game credits tothe balance at any time. The player may also optionally insert a loyaltyclub card into the card reader 230. During the game, the player viewswith one or more UIs, the game outcome on one or more of the primarygame display 240 and secondary game display 242. Other game and prizeinformation may also be displayed.

For each game instance, a player may make selections, which may affectplay of the game. For example, the player may vary the total amountwagered by selecting the amount bet per line and the number of linesplayed. In many games, the player is asked to initiate or select optionsduring course of game play (such as spinning a wheel to begin a bonusgame feature or select various items during a feature game). The playermay make these selections using the player-input buttons 236, theprimary game display 240 which may be a touch screen or using some otherdevice which enables a player to input information into the gamingdevice 200.

During certain game events, the gaming device 200 may display visual andauditory effects that can be perceived by the player. These effects addto the excitement of a game, which makes a player more likely to enjoythe playing experience. Auditory effects include various sounds that areprojected by the speakers 220. Visual effects include flashing lights,strobing lights or other patterns displayed from lights on the gamingdevice 200 or from lights behind the information panel 152 (FIG. 1 ).

When the player is done, he/she cashes out the credit balance (typicallyby pressing a cash out button to receive a ticket from the ticketprinter 222). The ticket may be “cashed-in” for money or inserted intoanother machine to establish a credit balance for play.

Additionally, or alternatively, gaming devices 104A-104X and 200 caninclude or be coupled to one or more wireless transmitters, receivers,and/or transceivers (not shown in FIGS. 1 and 2A) that communicate(e.g., Bluetooth® or other near-field communication technology) with oneor more mobile devices to perform a variety of wireless operations in acasino environment. Examples of wireless operations in a casinoenvironment include detecting the presence of mobile devices, performingcredit, points, comps, or other marketing or hard currency transfers,establishing wagering sessions, and/or providing a personalizedcasino-based experience using a mobile application. In oneimplementation, to perform these wireless operations, a wirelesstransmitter or transceiver initiates a secure wireless connectionbetween a gaming device 104A-104X and 200 and a mobile device. Afterestablishing a secure wireless connection between the gaming device104A-104X and 200 and the mobile device, the wireless transmitter ortransceiver does not send and/or receive application data to and/or fromthe mobile device. Rather, the mobile device communicates with gamingdevices 104A-104X and 200 using another wireless connection (e.g., WiFi®or cellular network). In another implementation, a wireless transceiverestablishes a secure connection to directly communicate with the mobiledevice. The mobile device and gaming device 104A-104X and 200 sends andreceives data utilizing the wireless transceiver instead of utilizing anexternal network. For example, the mobile device would perform digitalwallet transactions by directly communicating with the wirelesstransceiver. In one or more implementations, a wireless transmittercould broadcast data received by one or more mobile devices withoutestablishing a pairing connection with the mobile devices.

Although FIGS. 1 and 2A illustrate specific implementations of a gamingdevice (e.g., gaming devices 104A-104X and 200), the disclosure is notlimited to those implementations shown in FIGS. 1 and 2A. For example,not all gaming devices suitable for implementing implementations of thepresent disclosure necessarily include top wheels, top boxes,information panels, cashless ticket systems, and/or player trackingsystems. Further, some suitable gaming devices have only a single gamedisplay that includes only a mechanical set of reels and/or a videodisplay, while others are designed for bar counters or tabletops andhave displays that face upwards. Gaming devices 104A-104X and 200 mayalso include other processors that are not separately shown. Using FIG.2A as an example, gaming device 200 could include display controllers(not shown in FIG. 2A) configured to receive video input signals orinstructions to display images on game displays 240 and 242.Alternatively, such display controllers may be integrated into the gamecontroller 202. The use and discussion of FIGS. 1 and 2A are examples tofacilitate ease of description and explanation.

FIG. 2B depicts a casino gaming environment according to one example. Inthis example, the casino 251 includes banks 252 of EGMs 104. In thisexample, each bank 252 of EGMs 104 includes a corresponding gamingsignage system 254 (also shown in FIG. 2A). According to thisimplementation, the casino 251 also includes mobile gaming devices 256,which are also configured to present wagering games in this example. Themobile gaming devices 256 may, for example, include tablet devices,cellular phones, smart phones, dedicated gaming consoles, and/or otherhandheld or portable devices. In this example, the mobile gaming devices256 are configured for communication with one or more other devices inthe casino 251, including but not limited to one or more of the servercomputers 102, via wireless access points 258.

According to some examples, the mobile gaming devices 256 may beconfigured for stand-alone determination of game outcomes. However, insome alternative implementations the mobile gaming devices 256 may beconfigured to receive game outcomes from another device, such as thecentral determination gaming system server 106, one of the EGMs 104,etc.

Some mobile gaming devices 256 may be configured to accept monetarycredits from a credit or debit card, via a wireless interface (e.g., viaa wireless payment app), via tickets, via a patron casino account, etc.However, some mobile gaming devices 256 may not be configured to acceptmonetary credits via a credit or debit card. Some mobile gaming devices256 may include a ticket reader and/or a ticket printer whereas somemobile gaming devices 256 may not, depending on the particularimplementation.

In some implementations, the casino 251 may include one or more kiosks260 that are configured to facilitate monetary transactions involvingthe mobile gaming devices 256, which may include cash out and/or cash intransactions. The kiosks 260 may be configured for wired and/or wirelesscommunication with the mobile gaming devices 256. The kiosks 260 may beconfigured to accept monetary credits from casino patrons 262 and/or todispense monetary credits to casino patrons 262 via cash, a credit ordebit card, via a wireless interface (e.g., via a wireless payment app),via tickets, etc. According to some examples, the kiosks 260 may beconfigured to accept monetary credits from a casino patron and toprovide a corresponding amount of monetary credits to a mobile gamingdevice 256 for wagering purposes, e.g., via a wireless link such as anear-field communications link. In some such examples, when a casinopatron 262 is ready to cash out, the casino patron 262 may select a cashout option provided by a mobile gaming device 256, which may include areal button or a virtual button (e.g., a button provided via a graphicaluser interface) in some instances. In some such examples, the mobilegaming device 256 may send a “cash out” signal to a kiosk 260 via awireless link in response to receiving a “cash out” indication from acasino patron. The kiosk 260 may provide monetary credits to the casinopatron 262 corresponding to the “cash out” signal, which may be in theform of cash, a credit ticket, a credit transmitted to a financialaccount corresponding to the casino patron, etc.

In some implementations, a cash-in process and/or a cash-out process maybe facilitated by the TITO system server 108. For example, the TITOsystem server 108 may control, or at least authorize, ticket-in andticket-out transactions that involve a mobile gaming device 256 and/or akiosk 260.

Some mobile gaming devices 256 may be configured for receiving and/ortransmitting player loyalty information. For example, some mobile gamingdevices 256 may be configured for wireless communication with the playertracking system server 110. Some mobile gaming devices 256 may beconfigured for receiving and/or transmitting player loyalty informationvia wireless communication with a patron's player loyalty card, apatron's smartphone, etc.

According to some implementations, a mobile gaming device 256 may beconfigured to provide safeguards that prevent the mobile gaming device256 from being used by an unauthorized person. For example, some mobilegaming devices 256 may include one or more biometric sensors and may beconfigured to receive input via the biometric sensor(s) to verify theidentity of an authorized patron. Some mobile gaming devices 256 may beconfigured to function only within a predetermined or configurable area,such as a casino gaming area.

FIG. 2C is a diagram that shows examples of components of a system forproviding online gaming according to some aspects of the presentdisclosure. As with other figures presented in this disclosure, thenumbers, types, and arrangements of gaming devices shown in FIG. 2C aremerely shown by way of example. In this example, various gaming devices,including but not limited to end user devices (EUDs) 264 a, 264 b and264 c are capable of communication via one or more networks 417. Thenetworks 417 may, for example, include one or more cellular telephonenetworks, the Internet, etc. In this example, the EUDs 264 a and 264 bare mobile devices: according to this example the EUD 264 a is a tabletdevice and the EUD 264 b is a smart phone. In this implementation, theEUD 264 c is a laptop computer that is located within a residence 266 atthe time depicted in FIG. 2C. Accordingly, in this example the hardwareof EUDs is not specifically configured for online gaming, although eachEUD is configured with software for online gaming. For example, each EUDmay be configured with a web browser. Other implementations may includeother types of EUD, some of which may be specifically configured foronline gaming.

In this example, a gaming data center 276 includes various devices thatare configured to provide online wagering games via the networks 417.The gaming data center 276 is capable of communication with the networks417 via the gateway 272. In this example, switches 278 and routers 280are configured to provide network connectivity for devices of the gamingdata center 276, including storage devices 282 a, servers 284 a and oneor more workstations 570 a. The servers 284 a may, for example, beconfigured to provide access to a library of games for online game play.In some examples, code for executing at least some of the games mayinitially be stored on one or more of the storage devices 282 a. Thecode may be subsequently loaded onto a server 284 a after selection by aplayer via an EUD and communication of that selection from the EUD viathe networks 417. The server 284 a onto which code for the selected gamehas been loaded may provide the game according to selections made by aplayer and indicated via the player's EUD. In other examples, code forexecuting at least some of the games may initially be stored on one ormore of the servers 284 a. Although only one gaming data center 276 isshown in FIG. 2C, some implementations may include multiple gaming datacenters 276.

In this example, a financial institution data center 270 is alsoconfigured for communication via the networks 417. Here, the financialinstitution data center 270 includes servers 284 b, storage devices 282b, and one or more workstations 286 b. According to this example, thefinancial institution data center 270 is configured to maintainfinancial accounts, such as checking accounts, savings accounts, loanaccounts, etc. In some implementations one or more of the authorizedusers 274 a-274 c may maintain at least one financial account with thefinancial institution that is serviced via the financial institutiondata center 270.

According to some implementations, the gaming data center 276 may beconfigured to provide online wagering games in which money may be won orlost. According to some such implementations, one or more of the servers284 a may be configured to monitor player credit balances, which may beexpressed in game credits, in currency units, or in any otherappropriate manner. In some implementations, the server(s) 284 a may beconfigured to obtain financial credits from and/or provide financialcredits to one or more financial institutions, according to a player's“cash in” selections, wagering game results and a player's “cash out”instructions. According to some such implementations, the server(s) 284a may be configured to electronically credit or debit the account of aplayer that is maintained by a financial institution, e.g., an accountthat is maintained via the financial institution data center 270. Theserver(s) 284 a may, in some examples, be configured to maintain anaudit record of such transactions.

In some alternative implementations, the gaming data center 276 may beconfigured to provide online wagering games for which game credits maynot be exchanged for cash or the equivalent. In some such examples,players may purchase game credits for online game play, but may not“cash out” for monetary credit after a gaming session. Moreover,although the financial institution data center 270 and the gaming datacenter 276 include their own servers and storage devices in thisexample, in some examples the financial institution data center 270and/or the gaming data center 276 may use offsite “cloud-based” serversand/or storage devices. In some alternative examples, the financialinstitution data center 270 and/or the gaming data center 276 may relyentirely on cloud-based servers.

One or more types of devices in the gaming data center 276 (orelsewhere) may be capable of executing middleware, e.g., for datamanagement and/or device communication. Authentication information,player tracking information, etc., including but not limited toinformation obtained by EUDs 264 and/or other information regardingauthorized users of EUDs 264 (including but not limited to theauthorized users 274 a-274 c), may be stored on storage devices 282and/or servers 284. Other game-related information and/or software, suchas information and/or software relating to leaderboards, playerscurrently playing a game, game themes, game-related promotions, gamecompetitions, etc., also may be stored on storage devices 282 and/orservers 284. In some implementations, some such game-related softwaremay be available as “apps” and may be downloadable (e.g., from thegaming data center 276) by authorized users.

In some examples, authorized users and/or entities (such asrepresentatives of gaming regulatory authorities) may obtaingaming-related information via the gaming data center 276. One or moreother devices (such EUDs 264 or devices of the gaming data center 276)may act as intermediaries for such data feeds. Such devices may, forexample, be capable of applying data filtering algorithms, executingdata summary and/or analysis software, etc. In some implementations,data filtering, summary and/or analysis software may be available as“apps” and downloadable by authorized users.

Example Game Processing Architecture

FIG. 3 illustrates, in block diagram form, an implementation of a gameprocessing architecture that implements a game processing pipeline 300for the play of a game in accordance with various implementationsdescribed herein. As shown in FIG. 3 , the gaming processing pipeline300 starts with having a UI system 302 receive one or more player inputsfor the game instance. Based on the player input(s), the UI system 302generates and sends one or more RNG calls to a game processing backendsystem 314. Game processing backend system 314 then processes the RNGcalls with RNG engine 316 to generate one or more RNG outcomes, forexample random numbers. The RNG outcomes are then sent to the RNGconversion engine 320 to generate one or more game outcomes for the UIsystem 302 to display to a player. A gaming device, such as gamingdevices 104A-104X and 200 shown in FIGS. 1 and 2A, respectively, canimplement the game processing pipeline 300. Alternatively, portions ofthe game processing pipeline 300 can be implemented using a gamingdevice and one or more remote gaming devices, such as centraldetermination gaming system server 106 shown in FIG. 1 .

The UI system 302 includes one or more UIs that a player can interactwith. The UI system 302 could include one or more game play UIs 304, oneor more bonus game play UIs 308, and one or more multiplayer UIs 312,where each UI type includes one or more mechanical UIs and/or graphicalUIs (GUIs). In other words, game play UI 304, bonus game play UI 308,and the multiplayer UI 312 may utilize a variety of UI elements, such asmechanical UI elements (e.g., physical “spin” button or mechanicalreels) and/or GUI elements (e.g., virtual reels shown on a video displayor a virtual button deck) to receive player inputs and/or present gameplay to a player. Using FIG. 3 as an example, the different UI elementsare shown as game play UI elements 306A-306N and bonus game play UIelements 310A-310N.

The game play UI 304 represents a UI that a player typically interfaceswith for a base game. During a game instance of a base game, the gameplay UI elements 306A-306N (e.g., GUI elements depicting one or morevirtual reels in a reel area) are shown and/or made available to a user.In a subsequent game instance, the UI system 302 could transition out ofthe base game to one or more bonus game features. The bonus game play UI308 represents a UI that utilizes bonus game play UI elements 310A-310Nfor a player to interact with and/or view during a bonus game feature.In one or more implementations, at least some of the game play UIelement 306A-306N are similar to the bonus game play UI elements310A-310N. In other implementations, the game play UI element 306A-306Ncan differ from the bonus game play UI elements 310A-310N.

In one or more implementations, the game processing pipeline 300 canincorporate the example implementations described herein into varioustypes of reel games. In particular, a reel game includes a base reelgame shown with game play UI 304 or bonus reel game shown with bonusgame play UI 308. Generally, a base, or primary, reel game includes playthat involves spinning reels. A bonus reel game can add the possibilityof winning a relatively large payout. A bonus reel game may require anadditional wager, but typically does not. For purposes of thisdisclosure, a bonus reel game can be a type of supplemental game featurethe game processing pipeline 300 can implement.

For a reel game, the game play UI 304 and/or bonus game play UI 308includes a reel area that encloses viewable portions of a set of reelsassociated with the reel area. For each reel strip, the viewable portionof the reel strips includes one or more positions for symbols (alsoreferenced throughout the disclosure as “symbol window positions”).Thus, the reel area is a matrix of symbols on a UI and may behighlighted to emphasize reel strips and symbols within the reel area.The number of reel strips and dimensions of the reel area depend onimplementation. In some typical configurations, a reel area has an m×nconfiguration, with m reels and with n symbols visible per reel. Forexample, for a base reel game, a reel area can have a 5×3configuration—five reels per window, with three symbols showing in thewindow for each of the reels. More generally, the reel area spans mreels in a first dimension and spans n symbols in a second dimensionorthogonal to the first dimension, where the value of m can be 4, 5, 6,7, 8, or some other number of reels, and the value of n can be 2, 3, 4,5, 6, or some other number of symbols. Typically, the m reels arearranged horizontally in the reel area from left-to-right, with the mreels spinning vertically and the reel area showing n symbols of each ofthe respective reels. Alternatively, the m reels are arranged verticallyin the reel area from top-to-bottom, with the m reels spinninghorizontally and the reel area showing n symbols of each of therespective reels. Alternatively, a reel area can have anotherconfiguration. For example, a reel area can have different numbers ofsymbols visible for different reels (e.g., going left to right in a reelarea, two symbols visible for a leftmost reel, three symbols visible fora second reel, four symbols visible for a center reel, three symbolsvisible for a fourth reel, and two symbols visible for a rightmostreel), or as further explained below, a reel area can have a p×qconfiguration, with p×q reels visible in a rectangular reel area, and asingle symbol visible per reel.

FIG. 3 also illustrates that UI system 302 could include a multiplayerUI 312 purposed for game play that differs or is separate from thetypical base game. For example, multiplayer UI 312 could be set up toreceive player inputs and/or presents game play information relating toa tournament mode. When a gaming device transitions from a primary gamemode that presents the base game to a tournament mode, a single gamingdevice is linked and synchronized to other gaming devices to generate atournament outcome. For example, multiple RNG engines 316 correspondingto each gaming device could be collectively linked to determine atournament outcome. To enhance a player's gaming experience, tournamentmode can modify and synchronize sound, music, reel spin speed, and/orother operations of the gaming devices according to the tournament gameplay. After tournament game play ends, operators can switch back thegaming device from tournament mode to a primary game mode to present thebase game. Although FIG. 3 does not explicitly depict that multiplayerUI 312 includes UI elements, multiplayer UI 312 could also include oneor more multiplayer UI elements.

Based on the player inputs, the UI system 302 could generate RNG callsto a game processing backend system 314. As an example, the UI system302 could use one or more application programming interfaces (APIs) togenerate the RNG calls. To process the RNG calls, the RNG engine 316could utilize gaming RNG 318 and/or non-gaming RNGs 319A-319N. GamingRNG 318 could corresponds to RNG 212 or hardware RNG 244 shown in FIG.2A. As previously discussed with reference to FIG. 2A, gaming RNG 318often performs specialized and non-generic operations that comply withregulatory and/or game requirements. For example, because of regulationrequirements, gaming RNG 318 could correspond to RNG 212 by being acryptographic RNG or pseudorandom number generator (PRNG) (e.g., FortunaPRNG) that securely produces random numbers for one or more gamefeatures. To securely generate random numbers, gaming RNG 318 couldcollect random data from various sources of entropy, such as from anoperating system (OS) and/or a hardware RNG (e.g., hardware RNG 244shown in FIG. 2A). Alternatively, non-gaming RNGs 319A-319N may not becryptographically secure and/or be computationally less expensive.Non-gaming RNGs 319A-319N can, thus, be used to generate outcomes fornon-gaming purposes. As an example, non-gaming RNGs 319A-319N cangenerate random numbers for generating random messages that appear onthe gaming device.

The RNG conversion engine 320 processes each RNG outcome from RNG engine316 and converts the RNG outcome to a UI outcome that is feedback to theUI system 302. With reference to FIG. 2A, RNG conversion engine 320corresponds to RNG conversion engine 210 used for game play. Aspreviously described, RNG conversion engine 320 translates the RNGoutcome from the RNG 212 to a game outcome presented to a player. As anexample, in a reel game, to determine the random base game outcome, theRNG conversion engine 320 includes reel strips that vary in symbolpattern and reel strip length. Each reel strip includes x positionsalong a one-dimensional strip of symbols, where x depends onimplementation. For example, x is 30, 80, 100, 200, or some other numberof positions. The value of x can be the same or different for differentreels (thus, different reels can have different numbers of positions).Each reel can have a data structure (e.g., array, linked list) thattracks the symbols at the respective positions of the reel strip for thereel. In some example implementations, the configuration of the symbolsat the positions of the reel strips for the reels of a reel game isfixed after the reel game boots, although limited reconfigurationoperations may be permitted. In other example implementations, theconfiguration of the symbols at the positions of the reel strips for thereels of a reel game can change dynamically after the reel game boots(e.g., depending on bet level or some other factor). Different sets ofreels can be used for a base reel game and bonus reel game (or othersupplemental game feature such as a special mode of the base reel game).For example, for a special mode of a base reel game, more “valuable”symbols, such as wild symbols or scatter symbols, can be added to thereels of a base reel game or swapped in for other symbols on the reels.

RNG conversion engine 320 could also utilizes one or more lookup tables322A-322N, which are also called weighted tables, to regulate a prizepayout amount for each RNG outcome and how often the gaming device paysout the derived prize payout amounts. To do so, RNG conversion engine320 can determine various game outcomes and perform operations forvarious types of base game features and/or supplemental game features(e.g., a bonus game feature). Although not shown in FIG. 3 , the RNGconversion engine 320 could store and/or utilize one or more sets ofreel strips, where each set of reel strips has different reel strippatterns. The RNG conversion engine 320 can also store (e.g., as datastructures) and/or utilize one or more lookup tables 322 to assignprobabilities to different options. For example, the RNG conversionengine 320 selects one of the different options based on a random numberfor the RNG outcome, where the different options are represented indifferent entries of a lookup table 322.

In one or more implementations, for a given lookup table 322, theprobabilities for different options can be reflected in table entryvalues (e.g., for a random number RND associated with a RNG outcome,generated by an RNG, in the range of 0<RND<=40 for option 1, 40<RND<=70for option 2, 70<RND<=90 for option 3, and 90<RND<=100 for option 4,given four options and a random number RND where 0<RND<=100). The tableentry values can represent percentages or, more generally, sub-rangeswithin the range for a random number. In some implementations, the tableentry values for a lookup table 322 are represented as count values(which can also be referend throughout the disclosure as “weights”) forthe respective entries of the lookup table. As an example, the followingtable shows count values for the four options described above:

TABLE 1 Example Lookup Table count value entry 40 <value a1, value a2, .. . > 30 <value b1, value b2, . . . > 20 <value c1, value c2, . . . > 10<value d1, value d2, . . . >

The sum total of the count values indicates the range of the options.Game processing backend system 314 can use a random number for an RNGoutcome, generated between 1 and the sum total of the count values, toselect one of the entries in the lookup table 322 by comparing therandom number to successive running totals. In the example shown inTable 1, if the random number for the RNG outcome is 40 or less, the RNGconversion engine 320 selects the first entry. Otherwise, if the randomnumber for the RNG outcome is between 41 and 70, RNG conversion engine320 selects the second entry. Otherwise, if the random number for theRNG outcome is between 71 and 90, the RNG conversion engine 320 selectsthe third entry. Otherwise, the RNG conversion engine 320 selects thelast entry. The table entry values for a lookup table 322 can be fixedand predetermined, can vary dynamically (e.g., depending on bet level),or can be dynamically selected (e.g., depending on bet level, dependingon another factor) from among multiple available lookup tables.Different game parameters or choices during game play can use differentlookup tables 322, or different combinations of game parameters orchoices can be combined in entries of a given lookup table 322.

In general, after the reel strips have landed to produce a random basedgame outcome (also referenced throughout the disclosure as “reelstops”), game processing backend system 314 identifies any winconditions and any win amounts to award to the player (e.g., credited tothe player's credit balance). In some examples, win conditions depend ona count of credit symbols that land after the reel stops. In otherexamples, win conditions are defined as paylines (also called win lines)across at least a portion of a reel area on a display screen. For around of play, game processing backend system 314 awards a win amountwhen a certain combination of symbols appears along a payline. Winamounts can vary according to the combination of symbols and accordingto the particular payline along which the combination of symbols land.In one or more implementations, instead of evaluating win conditions onpaylines across reels, game processing backend system 314 can determinean award according to a “ways” approach. Game processing backend system314 typically determines the win amounts according to a pay table, wherethe pay table comprehends the various combinations of symbols and/orpaylines that may occur (e.g., the win conditions). The win amount for around of play may be a fraction of an amount wagered for that round ofplay for certain win conditions. For other win conditions, the winamount may be much larger than the amount wagered.

After generating the UI outcome, game processing backend system 314sends the UI outcome to the UI system 302. Examples of UI outcomes aresymbols to display on a video reel or reel stops for a mechanical reel.In one example, if the UI outcome is for a base game, the UI system 302updates one or more game play UI elements 306A-306N, such as symbols,for the game play UI 304. In another example, if the UI outcome is for abonus game feature, the UI system could update one or more bonus gameplay UI elements 310A-310N (e.g., symbols) for the bonus game play UI308. In response to updating the appropriate UI, the player maysubsequently provide additional player inputs to initiate a subsequentgame instance that progresses through the game processing pipeline 300.

Credit-Substitution Symbol Mechanics for Nonexpanding Reels

For purpose of this disclosure, the term “substitution symbol” refers toany symbol type that can be substituted for and/or act as one or moreother symbol types when determining a pay evaluation. Examples ofsubstitution symbols include plain-substitution symbols,credit-substitution symbols, and multiplier-substitution symbols, all ofwhich can also be generally referenced as “wild symbols.” The term“plain-substitution symbol” refers to a generic, substitution symboltype that substitutes for one or more other symbol types and is notassociated with multiple payout operations. Specifically, aplain-substitution symbol that substitutes for another symbol type toform a payline does not trigger an additional payout operation, butcould trigger an upgrade operation, bonus operation, or some otheroperation that provides an additional game benefit. The term“credit-substitution symbol” refers to a substitution symbol type withan assigned and/or determined credit value. In one or moreimplementations, a credit-substitution symbol can trigger payout of thecredit value in addition to a payline award when the credit-substitutionsymbol substitutes as another symbol type to form a payline. The term“multiplier-substitution symbol” refers to a substitution symbol typewith an assigned and/or determined multiplier value. In one or moreimplementations, the multiplier-substitution symbol triggers multiplyingthe payline award based on the multiplier value when themultiplier-substitution symbol is part of the payline. The term“add-substitution symbol supplemental feature” refers to a supplementalgame feature that adds substitution symbols to different symbol windowpositions in a displayed game area (e.g., reel area) over one or moregame instances.

With reference to FIG. 3 , to implement one or more credit-substitutionsymbol mechanics, the UI system 302 starts off by presenting a base gameto a player using game play UI 304. In a slot game context, game play UI304 includes a reel area with a set of reels, where each reel containsmultiple symbol window positions. After a player sets a wagering amountand initiates a game instance (can also be referred to within thisdisclosure as a “round of play” or for a slot game context as a “spin”),game play UI 304 presents to a player a random based game outcome. Forone or more game instances, rather than displaying the random based gameoutcome for the base game, game play UI 304 randomly transition to bonusgame play UI 308 to show an add-substitution symbol supplementalfeature. The bonus game play UI 308 can present the add-substitutionsymbol supplemental feature in a single game instance or over multiplegame instances. When presenting the add-substitution symbol supplementalfeature, the bonus game play UI 308 adds one or more substitutionsymbols (e.g., credit-substitution symbols and/or plain-substitutionsymbols) at one or more symbol window positions in the displayed reelarea. Bonus game play UI 308 can present the addition of substitutionsymbols using one or more animations that can occur when one or morereels are spinning or after the reels stop and before any payoutanimation occurs.

In one or more implementations, the UI system 302 can also present anadd-substitution symbol supplemental feature within a supplemental gamefeature (e.g., a free games bonus feature) using bonus game play UI 308.Similar to game play UI 304, in a slot game context, bonus game play UI308 includes a reel area with a set of reels, where each reel containsmultiple symbol window positions. For one or more game instances in thesupplemental game feature, bonus game play UI 308 randomly presents theadd-substitution symbol supplemental feature by placing one or moresubstitution symbols (e.g., credit-substitution symbols and/orplain-substitution symbols) at one or more symbol window positions inthe displayed reel area. Bonus game play UI 308 depicts the addition ofsubstitution symbols using one or more animations that can occur whenone or more reels are spinning or after the reels stop and before anypayout animation occurs.

To support presenting the add-substitution symbol supplemental featurewithin UI system 302, game processing backend system 314 randomlydetermines whether to trigger the add-substitution symbol supplementalfeature within a base game and/or supplemental game feature. In oneexample, game processing backend system 314 triggers theadd-substitution symbol supplemental feature based on the random basedgame outcome in the base game and/or supplemental game feature. Inanother example, game processing backend system 314 performs an RNG pullfrom a lookup table 322 (e.g., lookup table 322A) to trigger theadd-substitution symbol supplemental feature. For this example, the RNGpull is separate and independent from the RNG pulls that generate therandom based game outcome in the base game and/or supplemental gamefeature. The lookup table 322 (e.g., lookup table 322A) maps the RNGoutcome to a game evaluation that determines whether to trigger theadd-substitution symbol supplemental feature. Table 2, which is shownbelow, provides an example lookup table 322 for randomly determiningwhether to trigger the add-substitution symbol supplemental feature.

TABLE 2 Example Lookup Table for Triggering an Add-Substitution SymbolSupplemental Feature Count Value Triggering Event 300 Do Not Trigger aAdd-substitution symbol supplemental feature  1 Trigger Add-substitutionsymbol supplemental featureAs shown in Table 2, game processing backend system 314 is more likelyto not trigger the add-substitution symbol supplemental feature based onthe 300 count value (also referred to as the weighted value). By settingthe count values according to Table 2, game processing backend system314 can maintain a target game RTP since the add-substitution symbolsupplemental feature, on average, provides a higher payout than gameinstances in a base game and/or supplemental game feature.

After determining to trigger the add-substitution symbol supplementalfeature, game processing backend system 314 performs a randomsubstitution determination operation. As part of the random substitutiondetermination operation, game processing backend system 314 randomlydetermines the number of substitution symbols that should be assigned tosymbol window positions in a displayed gaming area. In a slot gamecontext, the displayed gaming area is a reel area with one or morereels, where each reel includes multiple symbol window positions. Foreach reel, game processing backend system 314 performs a separate RNGpull from a lookup table 322 (e.g., lookup table 322B) to randomlydetermine the number of substitution symbols to add to each reel. Forexample, if the reel area has five reels, then game processing backendsystem 314 performs five separate RNG pulls to determine the number ofsubstitution symbols to add for each reel. Specifically, game processingbackend system 314 performs one RNG pull for the reel positioned incolumn 1, a second RNG pull for the reel positioned in column 2, a thirdRNG pull for reel positioned in column 3, a fourth RNG pull for the reelpositioned in column 4, and a fifth RNG pull for the reel positioned incolumn 5. The five separate RNG pulls could be from a single lookuptable 322 (e.g., lookup table 322B) or from multiple lookup tables 322(e.g., separate lookup tables 322B-322F for each reel). By usingmultiple lookup tables 322 (e.g., lookup tables 322B-322F), gameprocessing backend system 314 could provide a finer granularity of gamevolatility control when compared to using a single lookup table 322.

In one or more implementations, game processing backend system 314performs a random substitution determination operation that directlydetermines the number of substitution symbols to add to a given reel.Table 3, which is shown below, provides an example lookup table 322(e.g., lookup table 322B) for directly determining the number ofsubstitution symbols to add for one or more reels. As shown in Table 3,for a given RNG pull, game processing backend system 314 maps an RNGoutcome to the number of substitution symbols to add to a given reel.

TABLE 3 Example Lookup Table for Determining the Number of SubstitutionSymbols to Add Count Number of Substitution Value Symbols to Add 10 0 501 10 2  5 3  1 4In Table 3, game processing backend system 314 is most likely to add onesubstitution symbol to a reel based on the count value of 50. Gameprocessing backend system 314 is least likely to add four substitutionsymbols based on the count value of one. With reference to Table 3, in a5×4 reel configuration, four is the maximum number of substitutionsymbols to add since each reel has a maximum number of four symbolwindow positions. In other implementations Table 3, could be weighteddifferently to be more likely to add a different number of substitutionsymbols. As an example, Table 3 could be constructed to provide a countvalue of 50 for adding two substitution symbols and a count value of 10for adding one substitution symbol. The count values set within Table 3allows game processing backend system 314 to maintain a target game RTPand/or achieve a certain game volatility.

After determining the number substitution symbols to add to each reel,as part of the random substitution determination operation, gameprocessing backend system 314 also randomly determines and assignssymbol window positions for the added substitution symbols. In one ormore implementations, game processing backend system 314 performs an RNGpull from a lookup table 322 (e.g., lookup table 322G) to randomlydetermine symbol window positions for the added substitution symbols.The lookup table maps an RNG outcome to an available symbol windowposition for a given reel. As an example, lookup table 322 (e.g., lookuptable 322G) could map the RNG outcome to four different symbol windowpositions in the left most reel (e.g., column 1) in the reel area. Basedon the RNG pull, game processing backend system 314 randomly determinesthe symbol window position for the given reel and assigns thesubstitution symbol to the determined symbol window position.Afterwards, for the given reel, game processing backend system 314removes the symbol window position from the list of available symbolwindow positions. Continuing with the example above, after determiningthat the top most symbol window position in the left most reel shouldreceive an added substitution symbol, game processing backend system 314removes the top most symbol window position at the left most reel fromthe list of available symbol window positions. When determining where toassign the next substitution symbol, game processing backend system 314randomly selects from the three other available symbol window positionsin the left most reel and assigns and/or places the added substitutionsymbol to the determined symbol window position. By removing unavailablesymbol window positions, game processing backend system 314 avoidsdetermining and assigning a substitution symbol at a symbol windowposition that already has been designated to receive an addedsubstitution symbol.

In one or more implementations, game processing backend system 314performs a random substitution determination operation that uses one ormore lookup tables 322 to indirectly determine the number ofsubstitution symbols to add to a given reel. Rather than determining thenumber of substitution symbols to add to a given reel, game processingbackend system 314 randomly determines which symbol window positionswill receive added substitution symbols. Based on the lookup tables 322,game processing backend system 314 randomly determines for each symbolwindow position whether to add a substitution symbol. In other words,game processing backend system 314 does not assign a symbol windowposition for a substitution symbol. Rather, for each symbol windowposition, game processing backend system 314 performs a separate RNGpull from lookup tables 322 that maps an RNG outcome to determinewhether to add substitution symbols. Afterwards, for each reel, gameprocessing backend system 314 counts the number of symbol windowpositions with added substitution symbols to indirectly determine thenumber of substitution symbols added to a given reel. Examples ofindirectly determining the number of substitution symbols to add to agiven reel is discussed later in the disclosure with respect to the reelgrowth, substitution determination operation.

Referring to FIG. 3 , lookup tables 322 can also include one or moresets of substitution volatility lookup tables. After game processingbackend system 314 determines to trigger the add-substitution symbolsupplemental feature, game processing backend system 314 also randomlydetermines which set of substitution volatility lookup tables to usewhen determining the substitution symbol types for the addedsubstitution symbols. For example, the substitution symbols could beplain-substitution symbols, credit-substitution symbols, and/or othermultiplier-substitution symbols. Having multiple sets of substitutionvolatility lookup tables increases the volatility of whencredit-substitution symbols and/or other substitution symbol types willland in the add-substitution symbol supplemental feature. As an example,the gaming device can have two sets of substitution volatility lookuptables, a first set of substitution volatility lookup tables thatrandomly selects credit-substitution symbols at a relatively higher ratethan a second set of substitution volatility lookup tables. Inparticular, when selecting the first set of volatility lookup tables,game processing backend system 314 could generate, on average, fivecredit-substitution symbols. In contrast, by selecting the second set ofvolatility lookup tables, game processing backend system 314 couldgenerate, on average, one credit-substitution symbol. Recall thatgenerating more credit-substitution symbols could increase gamevolatility by increasing the payout for each payline.

Each set of substitution volatility lookup tables includes a separatesubstitution volatility lookup table assigned to each reel displayed inthe reel area. For example, the left most reel (e.g., reel in column 1of the reel area) could have a substitution volatility lookup table thatis separate and independent of the substitution volatility lookup tablesfor one or more other reels (e.g., reels in columns 2-5 of the reelarea). Each substitution volatility lookup table could have differentweights assigned to credit-substitution symbols, plain-substitutionsymbols, and/or other substitution symbol types. After randomlyselecting one set of substitution volatility lookup tables anddetermining the number of substitution symbols to add to each reel, gameprocessing backend system 314 uses the assigned substitution volatilitylookup table to randomly determine whether each added substitutionsymbol for a given reel should be plain-substitution symbol,credit-substitution symbol, or other substitution symbol type.

One or more lookup tables 322 in FIG. 3 could also be credit volatilitylookup tables. For each credit-substitution symbol added to thedisplayed reel area, game processing backend system 314 randomlydetermines the credit values using a credit volatility lookup tableassociated with a given reel. In other words, game processing backendsystem 314 uses a separate credit volatility lookup table for each reelshown in the displayed reel area. As an example, reel in column 1 wouldbe assigned to one credit volatility lookup table, reel in column 2would be assigned to a second credit volatility lookup table, reel incolumn 3 would be assigned to a third credit volatility lookup table,and so forth. By having separate credit volatility lookup tables foreach reel, game processing backend system 314 can vary the credit valuesthat land across different reels. For example, the credit volatilitylookup tables are constructed such that, on average, higher creditvalues land on the reel in column 5 when compared to the other reels atother columns in the reel area. Additionally, or alternatively, reel incolumn 1 could also, on average, have lower credit values land whencompared to the other reels. Other implementations could utilize othercredit volatility lookup tables that dynamically determine the range ofthe credit values assigned for credit symbols (e.g., low, medium, orhigh game credit values).

As part of the add-substitution symbol supplemental feature, gameprocessing pipeline 300 initiates multiple RNG calls to determine therandom based game outcome for the add-substitution symbol supplementalfeature. For example, if the add-substitution symbol supplementalfeature includes five reels, game processing pipeline 300 initiates atotal of five RNG calls, one RNG call for each reel, to game processingbackend system 314 to determine the reel stop for each reel.Subsequently, game processing backend system 314 adds substitutionsymbols (e.g., credit-substitution symbols and/or plain-substitutionsymbols) over the random based game outcome at the appropriate symbolwindow positions. In other words, for each added substitution symbol,game processing backend system 314 replaces a symbol and/or combines thesymbol attributes of the symbol generated from the random based gameoutcome and the added substitutions symbol. As an example, gameprocessing backend system 314 can replace a variety of picture or royalsymbols generated from the random based game outcome with the addedsubstitution symbol. In another example, when game processing backendsystem 314 adds a substitution symbol over a feature triggering symbol(e.g., scatter symbol) at a given symbol window position, gameprocessing backend system 314 transforms the added substitution symbolto include both the symbol attribute for the feature triggering symbol(e.g., scatter symbol attribute) and for the substitution symbol (e.g.,wild symbol attribute). Another example involves adding a substitutionsymbol over a plain-wild symbol generated from the random based gameoutcome. In this example, game processing backend system 314 couldreplace the wild symbol generated from the random based game outcomewith the added substitution symbol. In another example, game processingbackend system 314 could combine the substitution symbol and wild symbolattributes to form an upgraded substitution symbol (e.g., substitutionsymbol with a ×2 multiplier value).

Following the addition of substitution symbols (e.g.,credit-substitution symbols and/or plain-substitution symbols) and thereels landing, bonus game play UI 308 presents one or more payoutanimations. In one or more implementation, for a plain-substitutionsymbol that forms a payline, bonus game play UI 308 presents a payoutanimation that pays out the corresponding payline award. For acredit-substitution symbol that forms a payline, bonus game play UI 308presents a payout animation that pays out the corresponding paylineaward and another payout animation that pays out the credit value of thecredit-substitution symbol. If the credit-substitution symbol isincluded in multiple paylines (e.g., four paylines), the bonus game playUI 308 presents multiple payout animations (e.g., four payoutanimations) that pays out the credit value of the credit-substitutionsymbol multiple times (four times). Other implementations could havebonus game play UI 308 present a payout animation based on paying outwith the “ways” approach.

To support the different payout animations for a givencredit-substitution symbol, game processing backend system 314 performsmultiple payout operations when a credit-substitution symbol substitutesfor another symbol type to form a payline. After determining that acredit-substitution symbol is part of a payline, game processing backendsystem 314 performs a payout operation using a pay table to determinethe payout amount for the payline. Using FIG. 3 as an example, one ofthe lookup tables 322 could be a pay table that determines payout for avariety of paylines for a game. In another payout operation, gameprocessing backend system 314 determines the credit value of thecredit-substitution symbol that is part of the payline. The credit valueof the credit-substitution symbol represents the payout amount for thepayline in the second payout operation.

In a slot game context, after performing the payout animations, bonusgame play UI 308 may present a re-spin feature that adds extrasubstitution symbols to the displayed reel area. In the re-spin feature,bonus game play UI 308 holds the substitution symbols already added tothe reels in the add-substitution symbol supplemental feature andpresents one or more re-spins of the reels. During a re-spin, bonus gameplay UI 308 adds one or more extra substitution symbols to the reels. Asan example, the bonus game play UI 308 presents holding fivesubstitution symbols that were previously added in the add-substitutionsymbol supplemental feature. As bonus game play UI 308 shows the reelspinning for the re-spin feature, the bonus game play UI 308 depicts oneor more animations that add two extra substitution symbols at twodifferent symbol window positions for a total of seven addedsubstitution symbols. After bonus game play UI 308 presents the reelsstopping and landing, bonus game play UI 308 provides one or more payoutanimations based on the presented random based game outcome and theseven added substitution symbols. In other gaming contexts, rather thanimplementing a re-spin feature, game processing backend system 314performs a re-play feature (e.g., a re-draw feature).

To determine whether to perform a re-spin feature, game processingbackend system 314 determines whether the results of theadd-substitution symbol supplemental feature satisfies a re-spin triggercondition. In one example, the re-spin trigger condition represents acondition where the re-spin feature will likely or guarantee generate atleast one payline regardless of the random based game outcome generatedfor the re-spin feature. In another example, the re-spin triggercondition represents a condition that guarantees a minimum payout amountfor a re-spin feature. Game processing backend system 314 compares there-spin trigger condition to whether the add-substitution symbolsupplemental feature has added enough substitution-symbols at therelevant symbol window positions and/or reels. For example, the re-spintrigger condition could require the add-substitution symbol supplementalfeature to have added from one to three substitution symbols on the reelin column 2 and from two to three substitution symbols on the reel incolumn 3 of the reel area.

Once game processing backend system 314 checks that the results of theadd-substitution symbol supplemental feature satisfy the re-spin triggercondition, game processing backend system 314 randomly determineswhether to trigger the re-spin feature. In one example, game processingbackend system 314 performs an RNG pull from a lookup table 322 that isseparate and independent from the RNG pulls that generate the randombased game outcome for the re-spin feature. The lookup table 322 fordetermining whether to trigger the re-spin feature could be similar toTable 2 by having one entry weighted to trigger the re-spin feature andanother entry weighted for not triggering the re-spin feature. Aftergame processing backend system 314 determines that the re-spin featureshould occur based on the lookup table 322, game processing backendsystem 314 randomly determines for each reel the number of extrasubstitution symbols to add and the type of substitution symbol. As anexample, game processing backend system 314 could directly determine thenumber of extra substitution symbols to add for each real using adifferent set of lookup tables with different weights. To determine thesubstitution symbol type, game processing backend system 314 could usethe same set of volatility lookup tables randomly selected in theadd-substitution symbol supplemental feature for the re-spin feature.Game processing backend system 314 then performs one or more payoutoperations after landing the reels and adding the extra substitutionsymbols to the reels.

FIGS. 4-6 are diagrams that depict example general layouts of UIsrelated to presenting add-substitution symbol sequences 400, 500, and600. The add-substitution symbol sequences 400, 500, and 600 depictadding plain-substitution symbols 415 and credit-substitution symbols416 to a reel area 404. Other implementations of the add-substitutionsymbol sequences 400, 500, and 600 could add other substitution symboltypes, such as multiplier-substitution symbols to other game areas. Agaming device can present add-substitution symbol sequences 400, 500,and 600 when executing a game program. Using FIG. 2A as an example, whena gaming device 200 executes game program 206, the gaming device 200displays bonus game play UIs 420, 440, 460, 520, 540, 560, 620, 640, and660 on primary game display 240 and/or secondary game display 242.Additionally, or alternatively, at least some or all portions of thebonus game play UIs 420, 440, 460, 520, 540, 560, 620, 640, and 660could be presented on mechanical reels and/or other types of mechanicaland/or electro-mechanical components not shown in FIG. 2A.

In FIGS. 4-6 , bonus game play UIs 420, 440, 460, 520, 540, 560, 620,640, and 660 include a reel area 404 with a 5×4 reel configuration. The5×4 reel configuration corresponds to five vertical reels 406, 408, 410,412, and 414 that are four symbols high. Reel 406 corresponds to theleft most vertical reel and reel 414 corresponds to the right mostvertical reel. For a given reel stop, reel area 404 presents a total of20 symbol window positions, where each reel in reel area 404 presentsfour symbol window positions. Other implementations of bonus game playUIs 420, 440, 460, 520, 540, 560, 620, 640, and 660 could have otherreel configurations (e.g., 5×3 reel configuration) that present adifferent number of symbol window positions (e.g., 15 symbol windowpositions) and/or include reels with different orientations (e.g., ahorizontal reel). Although bonus game play UIs 420, 440, 460, 520, 540,560, 620, 640, and 660 show blanks in certain symbol window positions,those blanks do not necessarily represent a blank symbol or no symbolslanding on those symbol window positions. Rather, the blank symbolscould be other symbol types (e.g., picture symbols or royal symbols)that are not shown to facilitate ease of discussion.

In a slot context, reels 406, 408, 410, 412, and 414 shown in FIGS. 4-6represent columns in reel area 404 that correspond to different reelstrips from a set of reel strips. For example, reel 406 is positioned incolumn 1 and corresponds to reel strip 1; reel 408 is positioned incolumn 2 and corresponds to reel strip 2; reel 410 is positioned incolumn 3 and corresponds to reel strip 3; reel 412 is positioned incolumn 4 and corresponds to reel strip 4; and reel 414 is positioned incolumn 5 and corresponds to reel strip 5. The reel strips (e.g., reelstrips 1-5) could have varying numbers of reel strip positions, wherethe total number of reel strips positions (e.g., more than 100 reelstrip positions) for each reel strip is greater than the reelconfiguration shown in reel area 404. Reels 406, 408, 410, 412, and 412act as vertical windows that display a portion of the reel strips whenpresenting the random based game outcome. Recall that a gaming devicedetermines a random based game outcome for a given game instance bymapping RNG outcomes to reel positions for a set of reel strips. Themapped reel positions on the reel strips represent reel stops that thegaming device then maps to symbol window positions in reels 406, 408,410, 412, and 414. As a result, adding substitution symbols to reels406, 408, 410, 412, and 412 at different symbol window positions differfrom adding substitution symbols to different reel strip positions onone or more reel strips.

With reference to FIG. 4 , the add-substitution symbol sequence 400presents an add-substitution symbol supplemental feature that addssubstitution symbols when reels 406, 408, 410, 412, and 414 arespinning. Bonus game play UI 420 represents an initial UI that depictsreels 406, 408, 410, 412, and 414 spinning in reel area 404 aftertriggering the add-substitution symbol supplemental feature. As shown inbonus game play UI 420, the downward pointing arrows represent that eachreel 406, 408, 410, 412, and 414 are spinning and that the random basedgame outcome has yet to be shown. While reels 406, 408, 410, 412, and414 are spinning, add-substitution symbol sequence 400 presents anadd-substitution symbol animation 450 to transition from bonus game playUI 420 to bonus game play UI 440. Specifically, the add-substitutionsymbol animation 450 adds one or more substitution symbols to one ormore symbol window positions while reels 406, 408, 410, 412, and 414 arespinning.

Bonus game play UI 440 represents a UI that follows completion of addingsubstitution symbols while reels 406, 408, 410, 412, and 414 arespinning. The downward pointing arrows in bonus game play UI 440 arestill present even after adding substitution symbols. The downwardpointing arrows are present in bonus game play UI 440 to indicate thatreels 406, 408, 410, 412, and 414 are still spinning. Bonus game play UI440 also presents a plain-substitution symbol 415 added to both reels406 and 408; two credit-substitution symbols 416 added to reel 410; nosubstitution symbols added to reel 412; and one credit-substitutionsymbol 416 added to reel 414.

The add-substitution symbol sequence 400 subsequently presents a randombased game outcome and payout animation 452 to transition from bonusgame play UI 440 to bonus game play UI 460. Bonus game play UI 460presents a random based game outcome that has been modified with theaddition of plain-substitution symbols 415 and credit-substitutionsymbols 416. Recall that plain-substitution symbols 415 andcredit-substitution symbols 416 added to a symbol window position canreplace and/or combine with the underlying symbols generated from therandom based game outcome. Using FIG. 4 as an example, bonus game playUI 460 shows an added plain-substitution symbol 415 that could havereplaced a royal symbol or picture symbol at the topmost symbol windowposition in reel 406. In another example, if the random based gameoutcome included a feature triggering symbol (e.g., a scatter symbol) atthe topmost symbol window position, the added plain-substitution symbol415 represents a symbol with combined symbol attributes.

Bonus game play UI 460 also illustrates a payline 462 that runs throughthe second row from the top of the reel area 404. In other words,payline 462 represents a horizontal payline that traverses across reels406, 408, 410, 412, and 414. In bonus game play UI 460, payline 462includes a plain-substitution symbol 415 and a credit-substitutionsymbol 416 on reels 408 and 410, respectively. Based oncredit-substitution symbol 416 on reel 408 being part of payline 462,bonus game play UI 460 presents two payout animations. One payoutanimation pays out the payline award for payline 462 and another payoutanimation pays out the credit value of credit-substitution symbol 416 onreel 410. Bonus game play UI 460 does not display an additional payoutanimation for the plain-substitution symbol 415 that is part of payline462. Although not shown in FIG. 4 , the add-substitution symbol sequence400 could include other payout animations for other paylines not shownin FIG. 4 .

In FIG. 5 , the add-substitution symbol sequence 500 presents anadd-substitution symbol supplemental feature that adds substitutionsymbols after reels 406, 408, 410, 412, and 414 stop. Similar to bonusgame play UI 420 shown in FIG. 4 , bonus game play UI 520 represents anUI that depicts reels 406, 408, 410, 412, and 414 spinning in reel area404 after triggering the add-substitution symbol supplemental feature.The downward pointing arrows in bonus game play UI 520 represent thateach reel 406, 408, 410, 412, and 414 are spinning and that the randombased game outcome has yet to land. Add-substitution symbol sequence 500also presents an add-substitution symbol animation 550 to transitionfrom bonus game play UI 520 to bonus game play UI 540. In contrast tothe add-substitution symbol animation 450 shown in FIG. 4 , theadd-substitution symbol and payout animation 550 adds one or moresubstitution symbols to one or more symbol window positions after reels406, 408, 410, 412, and 414 stop and present the random based gameoutcome.

Bonus game play UI 540 presents the random based game outcome beforeadding plain-substitution symbols 415 and credit-substitution symbols416 to symbol window positions. Similar to bonus game play UI 460 shownin FIG. 4 , the plain-substitution symbols 415 and credit-substitutionsymbols 416 have replaced and/or combined with symbols generated fromthe random based game outcome. Bonus game play UI 540 also illustratespayline 462 that runs through the second row from the top of reel area404 and includes a plain-substitution symbol 415 and acredit-substitution symbol 416. Because of credit-substitution symbol416, bonus game play UI 460 presents two payout animations. One payoutanimation depicts paying out the payline award determined for payline462 and another payout animation depicts paying out the credit value ofthe credit-substitution symbol 416 that is part of payline 462.

The add-substitution symbol sequence 500 subsequently presents payoutanimation 552 to transition from bonus game play UI 540 to bonus gameplay UI 560. The payout animation 552 causes bonus game play UI 560 todepict a diagonal payline 502 that traverses through reels 406, 408,410, 412, and 414. The diagonal payline 502 includes aplain-substitution symbol 415 located at the topmost symbol windowposition of reel 406 and the same credit-substitution symbol 416 locatedon reel 410 that was part of payline 462. Similar to payline 462, bonusgame play UI 560 presents two payout animations for diagonal payline502. One payout animation that awards the payline award determined fordiagonal payline 502 and another payout animation that awards the creditvalue of the credit-substitution symbol 416 that is part of payline 502.Bonus game play UI 560 does not present another payout animation for theplain-substitution symbol 415 that forms payline 502. Based on the twothe paylines 462 and 502 that traverses through the samecredit-substitution symbol 416 on reel 410, the add-substitution symbolsequence 500 performs two separate payout animations that pays out thecredit value of credit-substitution symbol 416 twice. Although not shownin FIG. 5 , the add-substitution symbol sequence 500 could include otherpayout animations for other paylines not shown in FIG. 5 .

The add-substitution symbol sequence 600 shown in FIG. 6 presents are-spin feature that adds extra substitution symbols to reels 406, 408,410, 412, and 414 after completing the add-substitution symbolsupplemental feature. Similar to bonus game play UI 560 shown in FIG. 5, bonus game play UI 620 represents an UI that depicts a random basedgame outcome after adding plain-substitution symbols 415 andcredit-substitution symbols 416 to symbol window positions. Based on therandom based game outcome, bonus game play UI 620 displays a diagonalpayline 502 that causes two separate payout animations, one payoutanimation for the payline award and another payout animation for thecredit value of credit-substitution symbol 416 on reel 410. Afterperforming the payout animations for the add-substitution symbolsupplemental feature, add-substitution symbol sequence 500 presents are-spin animation 650 that transitions the bonus game play UI 620 tobonus game play UI 640. The re-spin animation 650 causes bonus game playUI 640 to hold the plain-substitution symbols 415 andcredit-substitution symbols 416 added during the add-substitution symbolsupplemental feature while reels 406, 408, 410, 412, and 414 re-spin.

The random based game outcome and payout animation 652 causes bonus gameplay UI 660 to present a random based game outcome that has beenmodified with the plain-substitution symbols 415 and credit-substitutionsymbols 416 during the add-substitution symbol supplemental feature andthe extra plain-substitution symbols 415 and credit-substitution symbol416 added during the re-spin feature. In FIG. 6 , bonus game play UI 660illustrates that the random based game outcome and payout animation 652causes three extra substitution symbols to be added to reel area 404.Specifically, an extra plain-substitution symbol 415 is added on reel406, an extra plain-substitution symbol 415 is added on reel 412, and anextra credit-substitution symbol 416 is added on reel 414. Based on theextra substitution symbols, bonus game play UI 660 illustrates a newpayline 604 that that runs through the bottom row of reels 406, 408,410, 412, and 414. The payline 604 includes two credit-substitutionsymbols 416, one located on the reel in column 3 and the other locatedon the reel in column 5. Because of the two credit-substitution symbols416 part of payline 604, bonus game play UI 660 will present two payoutanimations that pay out the two credit values of credit-substitutionsymbols 416. Although not shown in FIG. 6 , the add-substitution symbolsequence 600 could include other payout animations for other paylinesnot shown in FIG. 6 .

FIG. 7 is an example screenshot of a bonus game play UI 700 thatcorresponds to a themed version of bonus game play UI 440 shown in FIG.4 . The bonus game play UI 700 has a substantially similar UI layout asbonus game play UI 440, but with additional graphical elementsassociated with the game's theme. For example, bonus game play UI 700depicts themed versions of the plain-substitution symbols and thecredit-substitution symbols. Moreover, similar to bonus game play UI440, bonus game play UI 440 presents a reel area 404 with 20 symbolwindow positions from a 5×4 reel configuration. Bonus game play UI 700also represents an UI that presents overlaying plain-substitutionsymbols 415 and credit-substitution symbols 416 over a random based gameoutcome. As shown in FIG. 7 , the credit-substitution symbols 416 inbonus game play UI 700 have varying credit values.

FIG. 8 is an example screenshot of a bonus game play UI 800 thatcorresponds to a themed version of bonus game play UIs 460, 540, 560,and 620 shown in FIGS. 4-6 . The bonus game play UI 800 has asubstantially similar UI layout as bonus game play UIs 460, 540, 560,and 620, but with additional graphical elements associated with thegame's theme. As shown in FIG. 8 , the bonus game play UI 800 displays apayline 802 that includes a credit-substitution symbol 416.Specifically, payline 802 includes the plain-wild substitution symbol415 located on the bottom left corner of reel 406, the nine symbollocated on reel 408, and the credit-substitution symbol 416 with acredit value of 300 on reel 410. The plain-wild substitution symbol 415,the nine symbol, and the credit-substitution symbol 416 within payline802 have win boxes around the symbols with short payline connectors thatconnect the win boxes. FIG. 8 also illustrates a line that travelsthrough the queen symbol on reel 412 and the ace symbol on the reel 414.Although the line appears to be part of payline 802, bonus game play UI800 does not present win boxes around the symbols to indicate thesymbols are not part of payline 802. For payline 802, bonus game play UI800 presents two payout animations, one payout animation that pays outthe payline award determined for payline 802 and another payoutanimation that pays out the credit value of credit-substitution symbol416.

FIG. 9 depicts a flowchart illustrating a UI based operation 900 forpresenting a add-substitution symbol supplemental feature triggered froma base game and/or supplement game feature. In one or moreimplementations, the UI based operation 900 may be implemented by a UIsystem 302 shown in FIG. 3 and/or displayed on the primary game display240 and secondary game display 242 of a gaming device 200 shown in FIG.2A. The UI based operation 900 also corresponds to the bonus game playUIs shown in FIGS. 4-8 . The use and discussion of FIG. 9 is only anexample to facilitate explanation and is not intended to limit thedisclosure to this specific example. Specifically, UI based operation900 does not necessarily need to perform the sequence of blocks in theorder as depicted in FIG. 9 . As an example, UI based operation 900 mayimplement blocks 904 and 906 concurrently rather than sequentially.Additionally, or alternatively, one or more of the blocks may beoptional and may not be performed in all implementations of UI basedoperation 900. For example, block 910 may be optional and may not beperformed when a re-spin feature fails to trigger.

UI based operation 900 may start at block 902 to present the initiationof a game instance. During the initiation of the game instance, UI basedoperation 900 may transition from a base game and/or supplemental gamefeature to an add-substitution symbol supplemental feature. In one ormore implementations, the reel configuration shown in a reel arearemains the same size. At block 904, UI based operation 900 presentsadding one or more credit-substitution symbols to one or more symbolwindow positions in a displayed reel area. As previously discussed, UIbased operation 900 may add credit-substitution symbols while the reelsare still spinning or after the reels land and present the random basedgame outcome. Recall that adding substitution symbols, such ascredit-substitution symbols, to symbol window positions differs fromadding substitution symbols to reel strip positions on reel strips. Forexample, adding substitution symbols to one or more reel strip positionson reel strips does not ensure the substitution symbols will land and beshown within the displayed reel area when presenting the random basedgame outcome.

From block 904, the UI based operation 900 moves to block 906 to presentthe credit-substitution symbols overlaid over the random based gameoutcome. Based on the overlay, the credit-substitution symbols caneither replace or combine with underlying symbols that land for a randombased game outcome. For example, if UI based operation 900 overlays acredit-substitution symbol over a feature trigger symbol, thecredit-substitution symbol acts both as a substitution symbol type andfeature trigger symbol type. UI based operation 900 may then proceed toblock 908 and present one or more payout animations that includecredit-substitution symbols. Based on the random based game outcome andthe overlaid credit-substitution symbols, UI based operation 900 maypresent two separate payout animations for each credit-substitutionsymbol that is part of a payline. One payout animation awards thepayline award and another payout animation that awards the credit valueof the credit-substitution symbol.

After performing the payout animations, UI based operation 900 moves toblock 910 and presents one or more re-spin features that add extracredit-substitution symbols. In one or more implementations, a re-spinfeature causes UI based operation 900 to hold the credit-substitutionsymbols added at block 904 while re-spinning the reels. UI basedoperation 900 can add extra credit-substitution symbols while the reelsare re-spinning or after the reels stop and preset another random basedgame outcome. Afterwards, UI based operation 900 presents payoutanimations for all paylines generated from the re-spin. Similar to block908, UI based operation 900 may present two separate payout animationsfor each credit-substitution symbol that is part of a payline.

FIG. 10 depicts a flowchart illustrating backend-based operation 1000for implementing one or more credit-substitution symbol mechanics. Forexample, backend-based operation 1000 includes a random substitutiondetermination operation that supports the UI based operation 900discussed with reference to FIG. 9 . In one or more implementations,backend-based operation 1000 may be implemented by a game processingbackend system 314 shown in FIG. 3 and/or by a game controller 202 shownin FIG. 2A. The use and discussion of FIG. 10 is only an example tofacilitate explanation and is not intended to limit the disclosure tothis specific example. In particular, backend-based operation 1000 doesnot necessarily need to perform the sequence of blocks in the order asdepicted in FIG. 10 . As an example, backend-based operation 1000 shownin FIG. 10 directly determines the number of substitution symbols to addto a given reel. Other implementations of backend-based operation 1000could indirectly determine the number of substitution symbols to add toa given reel by readjusting the sequence of blocks and/or not includingone or more of the blocks. Using FIG. 10 as an example, backend-basedoperation 1000 may not perform block 1006 when indirectly determiningthe number of substitution symbols to add to a given reel.

In FIG. 10 , backend-based operation 1000 implements acredit-substitution symbol mechanic presented by UI based operation 900shown in FIG. 9 . Backend-based operation 1000 may start at block 1002to randomly determine triggering an add-substitution symbol feature.With reference to FIG. 3 , Table 2 previously discussed is an examplelookup table backend-based operation 1000 may use to map the RNG outcometo a decision on whether to trigger the add-substitution symbolsupplemental feature. Other implementations of backend-based operation1000 could determine whether to trigger the add-substitution symbolfeature based on a generated random based game outcome. At block 1004,backend-based operation 1000 determines that if no add-substitutionsymbol feature triggers, backend-based operation 1000 ends. Otherwise,backend-based operation 1000 may move to block 1006.

To perform a random substitution determination operation, at block 1006,backend-based operation 1000 randomly determines the number ofsubstitution symbols to add to each reel in the displayed reel area.Specifically, backend-based operation 1000 directly determines thenumber of substitution symbols to add to a given reel by using a lookuptable that maps an RNG outcome to the number of substitution symbols toadd to the given reel. Table 3, which was previously shown, is anexample of a lookup table backend-based operation 1000 could use todetermine the number of substitution symbols to add to the given reel.In one or more implementations, backend-based operation 1000 uses asingle lookup table to determine the number of substitution symbols toadd to each reel. In other implementations, backend-based operation 1000uses multiple lookup tables, for example, a different lookup table foreach reel.

At block 1008, as part of the random substitution determinationoperation, backend-based operation 1000 randomly determines and assignsa symbol window position for each added substitution symbol. To randomlydetermine symbol window positions, backend-based operation 1000 performsan RNG pull from a lookup table that maps an RNG outcome to an availablesymbol window position for a given reel. In one or more implementations,the lookup table weights the available symbol window positions equally.When a backend-based operation 1000 determines the symbol windowposition for the substitution symbol, backend-based operation 1000places and/or assigns the substitution symbol to a specific windowposition in the given reel. Afterwards, for the given reel,backend-based operation 1000 removes the symbol window position from thelist of available symbol window positions. Removing unavailable symbolwindow positions allows backend-based operation 1000 to avoiddetermining and assigning a substitution symbol to a symbol windowposition that already has been assigned with another added substitutionsymbol.

At block 1010, as part of the random substitution determinationoperation, backend-based operation 1000 randomly determines if eachsubstitution symbol is a credit-substitution symbol. In one or moreimplementations, backend-based operation 1000 randomly determines whichset of substitution volatility lookup tables to use when determiningwhether to add plain-substitution symbols and/or credit-substitutionsymbols. In particular, backend-based operation 1000 can use a lookuptable that maps an RNG outcome to one of the sets of substitutionvolatility lookup tables. For example, the backend-based operation 1000can have two sets of substitution volatility lookup tables, one setconfigured to generate credit-substitution symbols at a relatively lowerrate than the second set of substitution volatility lookup tables. Thelookup table could be weighted to be more likely to select the set ofsubstitution volatility lookup tables with a relatively lower rate. Eachset of substitution volatility lookup tables includes separatesubstitution volatility lookup table for each reel displayed in the reelarea. After randomly selecting one set of substitution volatility lookuptables, backend-based operation 1000 uses the appropriate substitutionvolatility lookup table to randomly determine whether each addedsubstitution symbol for a given reel should be a credit-substitutionsymbol or some other substitution symbol type. For eachcredit-substitution symbol added to the displayed reel area, thebackend-based operation 1000 could also randomly determine the creditvalues using a credit volatility lookup table associated with a givenreel.

At block 1012, backend-based operation 1000 performs one or more payoutoperations that include credit-substitution symbols as part of the win.In a payline context, backend-based operation 1000 determines whichcredit-substitution symbol is part of a payline. For eachcredit-substitution symbol that is part of a payline, backend-basedoperation 1000 performs multiple payout operations. Backend-basedoperation 1000 performs one payout operation that determines the payoutamount for the payline according to a pay table. Using FIG. 3 as anexample, one of the lookup tables 322 could be a pay table thatdetermines payout for a variety of paylines for a game. In anotherpayout operation, backend-based operation 1000 determines the creditvalue of the credit-substitution symbol that is part of the payline. Thecredit value of the credit-substitution symbol represents the payoutamount for the payline for the other payout operation.

Credit-Substitution Symbol Mechanics with Reel Growth

In a slot game context, a gaming device can present an add-substitutionsymbol supplemental feature with reel growth over a single gameinstance. Returning to FIG. 3 as an example, to implement one or morecredit-substitution symbol mechanics that includes a reel growthoperation, UI system 302 starts off by presenting a base game to aplayer using game play UI 304. Game play UI 304 includes an initial reelarea with a set of reels arranged with an initial reel configuration,such as a 5×4 reel configuration. For one or more game instances, gameplay UI 304 randomly transition to bonus game play UI 308 to present anadd-substitution symbol supplemental feature with reel growth. Whenpresenting the add-substitution symbol supplemental feature with reelgrowth, bonus game play UI 308 modifies the reel configuration and addsone or more substitution symbols (e.g., credit-substitution symbolsand/or plain-substitution symbols) at one or more symbol windowpositions in the displayed reel area. Specifically, bonus game play UI308 can present one or more animations that expands the reel size andadds substitution symbols to one or more symbol window positions in theexpanded reel area and/or the initial reel area.

To support the add-substitution symbol supplemental feature with reelgrowth, game processing backend system 314 randomly determines whetherto trigger the add-substitution symbol supplemental feature with reelgrowth. In one or more implementations, to randomly trigger theadd-substitution symbol supplemental feature with reel growth within abase game and/or supplemental game feature, game processing backendsystem 314 performs an RNG pull from a lookup table 322 similar to Table2. The RNG pull that triggers the add-substitution symbol supplementalfeature is separate and independent from the RNG pulls that generate therandom based game outcome in the base game and/or supplemental gamefeature. In other words, game processing backend system 314 triggers theadd-substitution symbol supplemental feature with reel growthindependently and separately from the random based game outcome. Inother implementations, game processing backend system 314 triggers theadd-substitution symbol supplemental feature with reel growth based onthe random based game outcome generated within a game instance. As anexample, an add-substitution symbol supplemental feature with reelgrowth that occurs over multiple game instances may be randomlytriggered according to a random based game outcome (e.g., landing threescatter symbols in the reels).

After game processing backend system 314 determines to trigger theadd-substitution symbol supplemental feature, game processing backendsystem 314 performs a reel growth, substitution determination operation.For an add-substitution symbol supplemental feature that occurs within asingle spin, game processing backend system 314 performs a reel growth,substitution determination operation that randomly expands the reel sizeand adds substitution symbols. To maintain a target game RTP, gameprocessing backend system 314 links together multiple game evaluationsassociated with the reel growth, substitution determination operationusing a single lookup table and single RNG outcome. As an example, whengame processing backend system 314 performs an RNG pull from the lookuptable 322, the lookup table 322 maps the RNG outcome to the multiplegame evaluations: (1) the determined expanded reel size, (2) determinedreels with added substitution symbols, and (3) the substitution symboltypes for the added substitution symbols. Other examples could map theRNG outcome to other game evaluations, such as determined symbol windowpositions with substitution symbols.

Table 4 shown below represents an example lookup table that maps the RNGoutcome to the determined expanded reel size, determined reels withadded substitution symbols, and the substitution symbol types for thesubstitution symbols added to each reel. As shown in Table 4, the firsttable entry with a count value of 50 represents that the reel size willgrow from a 5×4 reel configuration to a 5×7 reel configuration while thethird table entry with a count value of 30 will grow to a 5×9 reelconfiguration. For both the first and third table entries, each reelwithin a reel area will have at least one plain-substitution symboladded to one or more of the reel's symbol window positions. Statedanother way, any substitution symbol that is added to any reel will be aplain-substitution symbol, not a credit-substitution symbol. Incontrast, for the last table entry with a count value of one, reels incolumns 3 and 4 of the reel area will have at least onecredit-substitution symbol added while reels in columns 1, 2, and 5 willhave at least one plain-substitution symbols added to the reels. Anysubstitution symbol added to reels in columns 3 and 4 will becredit-substitution symbols, and any substitution symbol added to reelsin columns 1, 2, and 5 will be plain-substitution symbols.

TABLE 4 Example Lookup Table for Determining Expansion Reel Size andSubstitution Symbols Added Count Reel Size/Reels with Substitution ValueSymbols/Substitution Symbol Types 50 5 × 7 reel size; Reels in columns1-5 have plain-substitution symbols added 40 5 × 8 reel size, Reels incolumns 1-5 have plain-substitution symbols added 30 5 × 9 reel size,Reels in columns 1-5 have plain-substitution symbols added  5 5 × 7 reelsize; Reels in columns 1, 2, 4, and 5 have plain-substitution symbolsadded; Reel in column 3 has credit-substitution symbols added  1 5 × 7reel size; Reels in columns 1, 2, and 5 have plain-substitution symbolsadded; Reels in columns 3 and 4 have credit-substitution symbols addedTable 4 may be only a portion of the lookup table 322 and could includeother entries that cover the different combinations of placingsubstitution symbols for different reel size and addingplain-substitution symbols and/or credit-substitution symbols across thedifferent reels. As an example, Table 4 could have entries that expandthe reels up to 14 rows and/or have credit-substitution symbols addedand assigned to symbol window positions for all reels. Otherimplementations of Table 4 could include table entries that map RNGoutcomes to other substitution symbol types.

In one or more implementations, the lookup table that links multiplegame evaluations associated with the reel growth, substitutiondetermination operation could also be configured to account for adesignated minimum number of reels that will have at least onesubstitution symbol added to the reels. As an example, Table 4 can beconstructed to add at least one substitution symbol to two or morereels. If the designated minimum number of reels that will have at leastone substitution symbol added to the reels is two reels, Table 4 willnot include table entries that represents adding substitution symbols toonly a single reel. Instead, Table 4 would map all RNG outcomes to tableentries that represent adding substitution symbols to at least tworeels. Designating a minimum number of reels that will have at least onesubstitution symbol added to the reels assists in increasing gamevolatility for the single game instance while maintaining a target gameRTP.

In one or more implementations, the lookup table that links multiplegame evaluations associated with the reel growth, substitutiondetermination operation could also be configured to assign certainsubstitution symbol types to a subset of the reels. Game processingbackend system 314, for example, could configure Table 4 and/or otherlookup tables to provide plain-substitution symbols to all reels andcredit-substitution symbols to reels in columns 3, 4, and/or 5. By doingso, Table 4 is unable to map an RNG outcome to a table entry thatdesignates credit-substitution symbols to be added to reels in columns 1and/or 2. In another example, plain-substitution symbols could be addedto reels in columns 1-4 and not to the reel in column 5. Designatingcertain reels to generate certain substitution symbol types could alsoincrease game volatility for the single game instance while maintaininga target game RTP.

After determining the expanded reel size and the substitution symboltype for substitution symbols added to the reels, game processingbackend system 314 determines, as part of the reel growth, substitutiondetermination operation, which symbol window positions will receivesubstitution symbols. In one or more implementations, rather thandirectly determining the number of substitution symbols to add to agiven reel, game processing backend system 314 indirectly determines thenumber of substitution symbols to add to a given reel. Specifically,game processing backend system 314 performs the reel growth,substitution determination operation by using one or more lookup tables322 to randomly determine which symbol window positions will receivesubstitution symbols. For example, for each symbol window position, gameprocessing backend system 314 performs a separate RNG pull from one ormore lookup tables 322 that maps an RNG outcome to whether or not gameprocessing backend system 314 should place and assign a substitutionsymbol. Afterwards, for each reel, game processing backend system 314counts the number of symbol window positions with added substitutionsymbols to indirectly determine the number of substitution symbols addedto the reel.

Using Table 4 as an example, game processing backend system 314 mayrandomly select the first table entry that indicates all reels will addplain-substitution symbols. Based on the selection, game processingbackend system 314 performs seven different RNG pulls for each reel,which equals to a total of 35 different RNG pulls for all five reels.Game processing backend system 314 performs seven different RNG pullsbecause the reel configuration expands from four rows to seven rows.Each RNG pull randomly determines whether to add a plain-substitutionsymbol to a specific window position. In other words, for each RNG pull,game processing backend system 314 maps the RNG outcome to whether asymbol window position should receive the plain-substitution symbol.

In one or more implementations, as part of the reel growth, substitutiondetermination operation, game processing backend system 314 can alsoaccount for a designated minimum number of substitution symbols thatshould be added to each reel based on the expanded reel size. Gameprocessing backend system 314 can be setup to increase the designatedminimum number of substitution symbols that should be added to each reelafter the reel configuration reaches a certain reel size. As an example,the designated minimum number of substitution symbols could be set toadd and assign two substitution symbols to each reel when the reel areaexpands to a 5×7 reel configuration. If the reel area expands to a 5×14reel configuration, the designated minimum number of substitutionsymbols could be set to add and assign four substitution symbols to eachreel. For any reel, if game processing backend system 314 fails tosatisfy the designated minimum number of substitution symbol to add fora given reel (e.g., two plain-substitution symbol), game processingbackend system 314 reperforms the RNG pulls for the given reel untilsatisfying the designated minimum number of substitution symbol to addfor the given reel.

If the game processing backend system 314 determines thatcredit-substitution symbols will be added to one or more reels, as partof the reel growth, substitution determination operation, gameprocessing backend system 314 utilizes one or more credit volatilitylookup tables that dynamically determine the range of the credit valuesassigned for credit symbols (e.g., low, medium, or high game creditvalues). Referring again to Table 4, if game processing backend system314 randomly selects table entry four indicating the reel in column 3will receive credit-substitution symbols, game processing backend system314 performs one or more separate RNG pulls to determine the creditvalues for each credit-substitution symbol assigned to a symbol windowposition. In one example, game processing backend system 314 may performan RNG pull from one lookup table 322 (e.g., lookup table 322K) todetermine whether the reel in column 3 will fall in the low, medium, orhigh game credit value range. Game processing backend system 314 thenperforms another RNG pull using a separate lookup table 322 (e.g.,lookup table 322L) that corresponds to the selected volatility range todetermine the credit value. Alternatively, as previously disclosed, gameprocessing backend system 314 could use separate credit volatilitylookup tables for each reel to determine the credit values.

After presenting the addition of substitution symbols (e.g.,credit-substitution symbols and/or plain-substitution symbols) and thereels landing, bonus game play UI 308 presents one or more payoutanimations. In one or more implementation, for a givenplain-substitution symbol that forms a payline, bonus game play UI 308does not present an additional payout animation on top of the paylineaward. For a given credit-substitution symbol that forms a payline,bonus game play UI 308 presents a payout animation that pays out thepayline award and another payout animation that pays out the creditvalue of the credit-substitution symbol. If the credit-substitutionsymbol is included in multiple paylines (e.g., four paylines), the bonusgame play UI 308 presents multiple payout animations (e.g., four payoutanimations) that pays out the credit value of the credit-substitutionsymbol multiple times (four times). Other implementations could havebonus game play UI 308 present a payout animation based on paying outwith the “ways” approach.

To support the different payout animations for a givencredit-substitution symbol, game processing backend system 314 performsmultiple payout operations when a credit-substitution symbol substitutesfor another symbol type to form a payline. After determining that acredit-substitution symbol is part of a payline, game processing backendsystem 314 performs a payout operation using a pay table to determinethe payout amount for the payline. Using FIG. 3 as an example, one ofthe lookup tables 322 could be a pay table that determines payout for avariety of paylines for a game. In another payout operation, gameprocessing backend system 314 determines the credit value of thecredit-substitution symbol that is part of the payline. The credit valueof the credit-substitution symbol represents the payout amount for thepayline in the second payout operation.

Based on the payout operations for the paylines, game processing backendsystem 314 determines a total payout for the add-substitution symbolsupplemental feature. In one or more implementations, game processingbackend system 314 can check whether the total payout amount exceeds athreshold payout amount. The threshold payout amount can be based on avariety of game parameters, such as bet level and/or bet multiplier. Forexample, if game processing backend system 314 determines that the totalpayout for the add-substitution symbol supplemental feature is less thantwo times the bet level, game processing backend system 314 reperformsthe reel growth, substitution determination operation. Game processingbackend system 314 could reperform the reel growth, substitutiondetermination operation until the total payout for the add-substitutionsymbol supplemental feature is at least three times the bet level. TheUI system 302 does not present the random based game outcomes generatedfrom the reel growth, substitution determination operations that fail toproduce a total payout that satisfies the threshold payout amount.Rather, UI system 302 presents the first random based game outcome wherethe total payout satisfies the threshold payout amount. Checking for aminimum total payout for maintains a target game RTP and a certain gamevolatility.

In one or more implementations, the UI system 302 can present anadd-substitution symbol supplemental feature with reel growth overmultiple game instances. Using FIG. 3 as an example, the UI system 302starts off by presenting a base game to a player using game play UI 304.For a given game instance, game play UI 304 presents a random based gameoutcome that triggers the add-substitution symbol supplemental featurewith reel growth and causes UI system 302 to transition to bonus gameplay UI 308. After transitioning, bonus game play UI 308 presents aninitial number of game instances (e.g., five initial game instances) forthe add-substitution symbol supplemental feature with reel growth. Thenumber of game instances increases for the add-substitution symbolsupplemental feature with reel growth when bonus game play UI 308presents a free game instance symbol (e.g., +1 spin symbol) during oneor more of the initial game instances. Bonus game play UI 308 includesan initial reel area with an initial reel configuration, such as a 5×4reel configuration, at the start of the first game instance. In one ormore of the initial game instances, during the first game instanceand/or other game instances, bonus game play UI 308 randomly expands thereel size and/or adds substitution symbols to one or more symbol windowpositions in the expanded reel area.

To present an add-substitution symbol supplemental feature with reelgrowth, game processing backend system 314 randomly triggers theadd-substitution symbol supplemental feature with reel growth. Similarto the previously described add-substitution symbol supplementalfeatures, game processing backend system 314 can randomly trigger theadd-substitution symbol supplemental feature with reel growth based onthe generated random based game outcome or a separate and independentRNG pull. After game processing backend system 314 determines to triggerthe add-substitution symbol supplemental feature, game processingbackend system 314 performs a reel growth, substitution determinationoperation. In particular, game processing backend system 314 performs areel growth, substitution determination operation that randomly expandsthe reel size and adds substitution symbols over multiple game instances(e.g., multiple spins).

When performing the reel growth, substitution determination operation,game processing backend system 314 randomly determines the reel size foreach of the initial game instances. In one or more implementations, gameprocessing backend system 314 performs an RNG pull from one or morelookup tables 322 that maps the RNG outcomes to certain reel sizes.Specifically, game processing backend system 314 performs a separate RNGpull for each of the initial game instances. Based on the RNG pull, gameprocessing backend system 314 determines a reel size for each gameinstance. For example, game processing backend system 314 could randomlydetermine the reel size for the first and the second game instance ofthe add-substitution symbol supplemental feature with reel growth is a5×7 reel configuration and 5×8 reel configuration, respectively. Fromthe random determination, game processing backend system 314 grows thereel by one row when transitioning from the first to the second gameinstance. The lookup tables 322 could be weighted such that at the firstfew initial game instances are more likely to select the smaller reelsizes (e.g., 5×7 or 5×8 reel configuration) and at the later gameinstances are more likely to be select the larger reel sizes (e.g., 5×13or 5×14 reel configuration).

Game processing backend system 314 can randomly select which gameinstances out of a set of initial game instances will add substitutionsymbols. In one or more implementations, game processing backend system314 performs an RNG pull from one or more lookup tables 322 that mapsthe RNG outcomes to whether certain game instances will add substitutionsymbols. The RNG pull to map whether the game instance will addsubstitution symbols are separate and independent from the RNG pulls fordetermining whether to increase the reel sizes. The lookup tables 322could also be configured with a minimum number of game instances thatwill add substitution symbols. As an example, lookup tables 322 could beset to add substitution symbols to three of the five initial gameinstances. Based on the minimum number of game instances that will addsubstitution symbols and the RNG outcomes, game processing backendsystem 314 can determine that a subset of the initial game instancesinclude adding substitution symbols.

As part of the reel growth, substitution determination operation, gameprocessing backend system 314 may link the reel growth determination towhether substitution symbols will be added to each of the initial gameinstances or vice versa. For example, if game processing backend system314 randomly determines that substitution symbols should not be added toa given game instances, game processing backend system 314 will notperform a separate random determination to establish whether reel growthoccurs. In another example, game processing backend system 314 randomlydetermines that substitution symbols should be added, game processingbackend system 314 performs a separate and independent RNG pull todetermine whether to expand the reel area. Other implementations couldhave game processing backend system 314 that does not link the reelgrowth determination to when substitution symbols are added in a gameinstance or vice versa.

For each game instance designated to add substitution symbols, gameprocessing backend system 314 determines which reels should receive thesubstitution symbols and the substitution symbol types for each reel.Table 5 shown below represents an example lookup table that maps the RNGoutcome to determined reels with added substitution symbols and thesubstitution symbol types added to each reel.

TABLE 5 Example Lookup Table for Determining Substitution Symbols AddedCount Reels with Substitution Symbols/ Value Substitution Symbol Types50 Reels in columns 1-5 have plain-substitution symbols added 40 Reelsin columns 1-5 have plain-substitution symbols added 30 Reels in columns1-5 have plain-substitution symbols added  5 Reels in columns 1, 2, 4,and 5 have plain-substitution symbols added; Reel in column 3 hascredit- substitution symbols added  1 Reels in columns 1, 2, and 5 haveplain-substitution symbols added; Reels in columns 3 and 4 havecredit-substitution symbols addedAs shown in Table 5, for both the first and third table entries, eachreel within a reel area will have a plain-substitution symbol added andassigned to one or more symbol window positions. In contrast, for thelast table entry with a count value of one, reels in columns 3 and 4 ofthe reel area will have credit-substitution symbols added and assignedto one or more symbol window positions while reels in columns 1, 2, and5 will have plain-substitution symbols added and assigned to one or moresymbol window positions. Similar to Table 4, Table 5 may be only aportion of the lookup table 322 and could include other entries thatcover the different combinations of placing substitution symbols foradding plain-substitution symbols and/or credit-substitution symbolsacross the different reels. Additionally, or alternatively, Table 5could incorporate other parameters, such as which reel strips willinclude free game instance symbols (e.g., +1 spin symbol). Similar toTable 4, other implementations of Table 5 could include table entriesthat map RNG outcomes to other substitution symbol types.

After determining the type of substitution symbols to add to each reel,as part of the reel growth, substitution determination operation, gameprocessing backend system 314 determines which symbol window positionswill receive substitution symbols. In one or more implementations, gameprocessing backend system 314 can directly or indirectly determine thenumber of substitution symbols to add to a given reel as previouslydescribed. Game processing backend system 314 may also account for adesignated minimum number of substitution symbols that should be addedto each reel. Other implementations, in contrast, may not account for adesignated minimum number of substitution symbols that should be addedto each reel. If the game processing backend system 314 determines thatcredit-substitution symbols will be added to one or more reels, as partof the reel growth, substitution determination operation, gameprocessing backend system 314 utilizes one or more credit volatilitylookup tables to randomly determine the credit values. Game processingbackend system 314 also performs two payout operations, one payout forthe payline value and another payout for the credit value for thecredit-substitution symbol, each time a credit-substitution symbol ispart of a payline.

FIGS. 11-13 are diagrams that depict example general layouts of UIsrelated to presenting add-substitution symbol sequences 1100, 1200, and1300. Specifically, the add-substitution symbol sequences 1100, 1200,and 1300 depict adding plain-substitution symbols 415 andcredit-substitution symbols 416 to expanding reel areas 1102, 1302, and1304. Other implementations of the add-substitution symbol sequences1100, 1200, and 1300 could add other substitution symbol types, such asmultiplier-substitution symbols, to reel areas 1102, 1302, and 1304 orother types of game areas. A gaming device can present add-substitutionsymbol sequences 1100, 1200, and 1300 when executing a game program.Using FIG. 2A as an example, when a gaming device 200 executes gameprogram 206, the gaming device 200 displays bonus game play UIs 1140,1160, 1240, 1260, 1340, and 1360 on primary game display 240 and/orsecondary game display 242. Additionally, or alternatively, at leastsome or all portions of the bonus game play UIs 1140, 1160, 1240, 1260,1340, and 1360 could be presented on mechanical reels and/or other typesof mechanical and/or electro-mechanical components not shown in FIG. 2A.

In FIGS. 11-13 , bonus game play UIs 1140, 1160, 1240, 1260, 1340, and1360 include expanded reel areas 1102, 1302, and 1304. The expanded reelareas 1102, 1302, and 1304 include five vertical reels 406, 408, 410,412, and 414 with symbol heights that are greater than the initialsymbol heights of reel area 404. Similar to the UIs shown in FIGS. 4-6 ,bonus game play UIs 1140, 1160, 1240, 1260, 1340, and 1360 show blanksin certain symbol window positions. The blanks do not necessarilyrepresent a blank symbol or no symbols landing on those symbol windowpositions. Instead, the blanks represent other symbol types that are notshown to facilitate ease of discussion.

With reference to FIG. 11 , the add-substitution symbol sequence 1100presents an add-substitution symbol supplemental feature that expandsthe reel size and adds substitution symbols to the expanded reel area1102. Game play UI 1120 represents an initial UI that depicts reels 406,408, 410, 412, and 414 in reel area 404 in a base game and/orsupplemental game feature prior to triggering the add-substitutionsymbol supplemental feature. As shown in game play UI 1120, each reel406, 408, 410, 412, and 414 are four symbols high to form a 5×4 reelconfiguration. Add-substitution symbol sequence 1100 transitions fromgame play UI 1120 to bonus game play UI 1140 by presenting anadd-substitution symbol feature animation 1150. In FIG. 11 , theadd-substitution symbol feature animation 1150 performs a reel growthanimation that transforms reel area 404 to reel area 1102.

Bonus game play UI 1140 represents a UI after triggering theadd-substitution symbol feature and when the reels 406, 408, 410, 412,and 414 are spinning. When entering the add-substitution symbol feature,bonus game play UI 1140 presents reel area 1102 has expanded to a 5×8reel configuration. For a given reel stop, reel area 1102 now presents atotal of 40 symbol window positions, where each reel in reel area 1102presents eight symbol window positions. In one or more implementations,after entering the add-substitution symbol feature, reels 406, 408, 410,412, and 414 grow after initiating the game instances. Otherimplementations could have reels 406, 408, 410, 412, and 414 grow priorto spinning reels 406, 408, 410, 412, and 414 or grow after reels 406,408, 410, 412, and 414 have stopped spinning.

The add-substitution symbol sequence 1100 subsequently presents a randombased game outcome and add substitution symbol animation 1152 totransition from bonus game play UI 1140 to bonus game play UI 1160.Bonus game play UI 1160 presents a random based game outcome that hasbeen modified with the addition of plain-substitution symbols 415 andcredit-substitution symbols 416. The random based game outcome and addsubstitution symbol animation 1152 can add the substitution symbolswhile reels 406, 408, 410, 412, and 414 are spinning or after reels 406,408, 410, 412, and 414 stop. Recall that plain-substitution symbols 415and credit-substitution symbols 416 added to a symbol window positioncan replace and/or combine with the underlying symbols generated fromthe random based game outcome. Using FIG. 11 as an example, bonus gameplay UI 460 shows an added plain-substitution symbol 415 that could havereplaced a royal symbol or picture symbol at the topmost symbol windowposition in the expanded reel 406. In another example, if the randombased game outcome includes a feature triggering symbol (e.g., a scattersymbol) at the topmost symbol window position, the addedplain-substitution symbol 415 represents a symbol with combined symbolattributes.

In FIG. 12 , the add-substitution symbol sequence 1200 presents anadd-substitution symbol supplemental feature that presents multiplepaylines 1202 and 1204. The multiple paylines 1202 and 1204 occur afterpresenting a reel growth and adding substitution symbols to reels 406,408, 410, 412, and 414. Similar to game play UI 1120 shown in FIG. 11 ,game play UI 1220 represents an initial UI that depicts reels 406, 408,410, 412, and 414 in reel area 404 in a base game and/or supplementalgame feature prior to triggering the add-substitution symbolsupplemental feature. As shown in game play UI 1220, each reel 406, 408,410, 412, and 414 are four symbols high to form a 5×4 reelconfiguration. Add-substitution symbol sequence 1200 transitions fromgame play UI 1220 to bonus game play UI 1240 by presenting anadd-substitution symbol feature animation 1250.

The add-substitution symbol feature animation 1250 in FIG. 12 performs areel growth animation that transforms reel area 404 to reel area 1102.From the reel growth animation reel area 1202 has grown to a 5×8 reelconfiguration. Moreover, add-substitution symbol feature animation 1250presents a random based game outcome and adds substitution symbols. Asshown in FIG. 12 , bonus game play UI 1240 includes plain-substitutionsymbols 415 and credit-substitution symbols 416 that are overlaid ontothe random based game outcome. In other words, bonus game play UI 1240presents a random based game outcome that has been modified with theaddition of plain-substitution symbols 415 and credit-substitutionsymbols 416. The add-substitution symbol feature animation 1250 can addthe substitution symbols while reels 406, 408, 410, 412, and 414 arespinning or after reels 406, 408, 410, 412, and 414 stop.

The add-substitution symbol feature animation 1250 can also display apayout animation based on payline 1202. With reference to FIG. 12 , thepayout animation causes bonus game play UI 1240 to depict a horizontalpayline 1202 that traverses through reels 406, 408, 410, 412, and 414.In one or more implementations, bonus game play UI 1240 presents twopayout animations for payline 1202. One payout animation that awards thepayline award determined for payline 1202 and another payout animationthat awards the credit values of the credit-substitution symbols 416that are part of payline 1202. In other implementations, bonus game playUI 1240 could have previously present one payout animation that awardsall credit values of the credit-substitution symbols 416 that are partof payline (e.g., payline 1202). For example, bonus game play UI 1240could present credit payouts for credit-substitution symbols placed onthe reels (e.g., reel 410) that form payline 1202 and/or other paylines.Afterwards, bonus game play UI 1240 presents another payout animationthat awards payouts for each payline (e.g., payline 1202).

Add-substitution symbol sequence 1200 transitions from bonus game playUI 1240 to bonus game play UI 1260 by presenting another payoutanimation 1252 for another payline 1204. Similar to payline 1202, bonusgame play UI 1260 could also present two payout animations for payline1204. One payout animation that awards the payline award determined forpayline 1204 and another payout animation that awards the credit valuesof the credit-substitution symbols 416 that are part of payline 1204.Additionally, or alternatively, bonus game play UI 1260 could havepreviously present one payout animation that awards all credit values ofthe credit-substitution symbols 416 that are part of payline (e.g.,payline 1204). Afterwards, bonus game play UI 1260 presents anotherpayout animation that awards payouts for each payline (e.g., payline1204).

FIG. 13 illustrates an add-substitution symbol sequence 1300 thatexhibits an add-substitution symbol supplemental feature over multiplegame instances. Similar to game play UI 1120 shown in FIG. 11 , gameplay UI 1320 represents an initial UI that depicts reels 406, 408, 410,412, and 414 in reel area 404 in a base game and/or supplemental gamefeature prior to triggering the add-substitution symbol supplementalfeature. Reels 406, 408, 410, 412, and 414 present a random based gameoutcome that lands three feature triggering symbols 1310 (e.g., scattersymbols) that triggers the add-substitution symbol supplemental feature.Based on landing the three feature triggering symbols 1310,add-substitution symbol sequence 1300 transitions from game play UI 1320to bonus game play UI 1340 through an add-substitution symbol featureanimation 1350.

Bonus game play UI 1340 presents the random based game outcome for afirst game instance of a set of initial game instances. As shown in FIG.13 , bonus game play UI 1340 presents the random based game outcome in a5×7 reel configuration with plain-substitution symbols 415 andcredit-substitution symbols 416. To transition to bonus game play UI1340, add-substitution symbol feature animation 1350 displays a reelgrowth animation during the first game instance. In particular,add-substitution symbol feature animation 1350 transforms reel area 404,which has a 5×4 reel configuration, to reel area 1302, which has a 5×7reel configuration. Furthermore, add-substitution symbol featureanimation 1350 adds and overlays the substitution symbols while reels406, 408, 410, 412, and 414 are spinning or after reels 406, 408, 410,412, and 414 stop spinning.

Bonus game play UI 1340 also present a payout animation based on payline1306. Similar to bonus game play UI 1240, bonus game play UI 1340 canpresent two payout animations for a given payline, such as payline 1306.One payout animation awards the payline award determined for payline1306 and another payout animation awards the credit values of thecredit-substitution symbols 416 that are part of payline 1306. Otherimplementations, bonus game play UI 1340 could skip the payout animationthat awards the payline award and instead present payout animations thatawards the credit values of the credit-substitution symbols 416 that arepart of payline 1306.

Add-substitution symbol sequence 1300 transitions from bonus game playUI 1340 to bonus game play UI 1360 by presenting a game instanceprogression animation 1352. The game instance progression animation 1352presents a subsequent game instance after ending the first gameinstance. As an example, after presenting bonus game play UI 1340, agaming device receives a player input to initiate another game instance.Afterwards, game instance progression animation 1352 presents anotherreel growth animation without adding substitution symbols onto reels406, 408, 410, 412, and 414. Recall that a gaming device can implement areel growth, substitution determination operation that independentlydetermines whether reel growth occurs and whether substitution symbolswill be added to a given game instance. As a result, bonus game play UI1360 includes a reel area 1304 that has expanded to a reel configurationof 5×8 even though no substitution symbols have been added to reel area1304. Other implementations could link the reel growth animation whenadding substitution symbols to symbol window positions. As an example,adding substitution symbols could randomly trigger and/or cause theexpansion of reel area 1304.

FIG. 14 is an example screenshot of a bonus game play UI 1400 thatcorresponds to a themed version of bonus game play UI 1160 shown in FIG.11 . The bonus game play UI 1400 has a substantially similar UI layoutas bonus game play UI 1160, but with additional graphical elementsassociated with the game's theme. As shown in FIG. 14 , the bonus gameplay UI 1400 displays an expanded reel area 1102 with a reelconfiguration of 5×10. Bonus game play UI 1400 also represents an UIthat presents overlaying plain-substitution symbols 415 andcredit-substitution symbols 416 over a random based game outcome.

FIG. 15 is an example screenshot of a bonus game play UI 1500 thatcorresponds to a themed version of bonus game play UIs 1240 and 1260shown in FIG. 12 . Bonus game play UI 1500 has a substantially similarUI layout as bonus game play UIs 1240 and 1260, but with additionalgraphical elements associated with the game's theme. As shown in FIG. 15, the bonus game play UI 1500 displays a payline 1502 that includes acredit-substitution symbol 416. Specifically, payline 1502 is v-shapedand includes a plain-wild substitution symbol 415 located on the secondfrom the top symbol window position on reel 406, a plain-wildsubstitution symbol 415 located on the reel 408, a credit-substitutionsymbol 416 with a credit value of 150 on reel 410, a picture symbol onthe reel 412, and a credit-substitution symbol 416 with a credit valueof 200 on reel 414. The plain-wild substitution symbols 415, picturesymbol, and credit-substitution symbols 416 within payline 1512 havehighlighted win boxes around the symbols. For payline 1502, bonus gameplay UI 1500 presents two payout animations, one payout animation thatpays all the credit values for credit-wild symbols that part of apayline (e.g., payline 1512) and another payout animation that payouteach payline award determined for each payline (e.g., payline 1502).

FIG. 16 depicts a flowchart illustrating a UI based operation 1600 forpresenting a add-substitution symbol supplemental feature triggered froma base game and/or supplement game feature. In one or moreimplementations, the UI based operation 1600 may be implemented by a UIsystem 302 shown in FIG. 3 and/or displayed on the primary game display240 and secondary game display 242 of a gaming device 200 shown in FIG.2A. The UI based operation 1600 also corresponds to the game play UIsand bonus game play UIs shown in FIGS. 11-13 . The use and discussion ofFIG. 11 is only an example to facilitate explanation and is not intendedto limit the disclosure to this specific example. In particular, UIbased operation 1600 does not necessarily need to perform the sequenceof blocks in the order as depicted in FIG. 16 . As an example, UI basedoperation 1600 may implement block 1608 after implementing block 1610.Additionally, or alternatively, one or more of the blocks may beoptional and may not be performed in all implementations of UI basedoperation 1600. For example, blocks 1606, 1610, and 1612 may be optionaland may not be performed in all game instances of the add-substitutionsymbol supplemental feature.

UI based operation 1600 may start at block 1602 to present theinitiation of a game instance. The game instance could be for a gameinstance in a base game and/or a supplemental feature game feature. UIbased operation 1600 may then move to block 1604 to present an animationto transition to an add-substitution symbol supplemental feature. Duringthe initiation of the game instance, UI based operation 1600 maytransition from the base game and/or supplemental game feature to anadd-substitution symbol supplemental feature. The add-substitutionsymbol supplemental feature may occur over a single game instance ormultiple game instances.

At block 1606, UI based operation 1600 may present an adjustment of thereel size for reels in the reel area. For an add-substitution symbolsupplemental feature that occurs over a single game instance, UI basedoperation 1600 shows an increase of the reel size for the single gameinstance. In an add-substitution symbol supplemental feature that occursover multiple game instances, UI based operation 1600 may present anincrease of the reel size for a subset of the multiple game instances.As an example, UI based operation 1600 does not increase the reel sizein a first game instance in the add-substitution symbol supplementalfeature but increase the reel size in one or more subsequent gameinstances. Alternatively, UI based operation 1600 increases the reelsize in a first game instance in the add-substitution symbolsupplemental feature but fails to increase the reel size in one or moresubsequent game instances.

At block 1608, UI based operation 1600 presents a random based gameoutcome within the reel area. The reel area can include the initial reelarea prior to triggering the add-substitution symbol supplementalfeature and/or the expanded portion of the reel area. UI based operation1600 may then move to block 1610 and present adding one or morecredit-substitution symbols. The UI based operation 1600 can add the oneor more credit-substitution symbols in the initial reel area and/or theexpanded portion of the reel area. As an example, UI based operation1600 may add credit-substitution symbols in the expanded portion of thearea but not in the initial reel area. In another example, UI basedoperation 1600 may add credit-substitution symbols in the initial reelarea and not the expanded portion of the reel area. UI based operation1600 may add credit-substitution symbols while the reels are stillspinning and before presenting the random based game outcome or afterdisplaying the random based game outcome.

Afterwards, UI based operation 1600 may present one or more payoutanimations that include the credit-substitution symbols. Referring toFIG. 15 , UI based operation 1600 can display a bonus game play UI 1500that shows a payline 1502 with a credit-substitution symbol 416. Forpayline 1502, bonus game play UI 1500 presents two payout animations,one payout animation that pays out the payline award determined forpayline 1502 and another payout animation that pays out the credit valueof credit-substitution symbol 416. Alternatively, UI based operation1600 could skip the payout animation that awards the payline award andinstead present payout animations that awards the credit values of thecredit-substitution symbols 416 that are part of payline 1502

FIG. 17 depicts a flowchart illustrating backend-based operation 1700for implementing one or more credit-substitution symbol mechanics overone or more game instances. For example, backend-based operation 1700includes a reel growth, substitution determination operation thatsupports the UI based operation 1600 discussed with reference to FIG. 16. In one or more implementations, backend-based operation 1700 may beimplemented by a game processing backend system 314 shown in FIG. 3and/or by a game controller 202 shown in FIG. 2A. The use and discussionof FIG. 17 is only an example to facilitate explanation and is notintended to limit the disclosure to this specific example. Inparticular, backend-based operation 1700 does not necessarily need toperform the sequence of blocks in the order as depicted in FIG. 17 . Asan example, backend-based operation 1700 shown in FIG. 17 could performblocks 1706, 1708, and 1710 simultaneously or in another sequence order,for example, blocks 1708 and 1710 are performed before block 1706. Otherimplementations of backend-based operation 1700 could directly determinethe number of substitution symbols to add to a given reel by readjustingthe sequence of blocks and/or not including one or more of the blocks.

Backend-based operation 1700 starts at block 1702 to randomly determinetriggering an add-substitution symbol feature. With reference to FIG. 3, Table 2 previously discussed is an example lookup table backend-basedoperation 1700 may use to map the RNG outcome to a decision on whetherto trigger the add-substitution symbol supplemental feature. Otherimplementations of backend-based operation 1700 could determine whetherto trigger the add-substitution symbol feature based on a generatedrandom based game outcome. Using FIG. 13 as an example, backend-basedoperation 1700 can generate a random based game outcome that lands threefeature triggering symbols 1310 that triggers the add-substitutionsymbol feature. At block 1704, backend-based operation 1700 determinesthat if no add-substitution symbol feature triggers, backend-basedoperation 1700 ends. Otherwise, backend-based operation 1700 may move toblock 1706.

To execute a reel growth, substitution determination operation, at block1706, backend-based operation 1700 randomly determines the reel size forreels in the reel area. In one example, backend-based operation 1700links the game evaluation of the determined expanded reel size to othergame evaluations, such as determined reels with added substitutionsymbols and substitution symbol types for the added substitution symbolsassociated with the reel growth. Backend-based operation 1700 could linkthe reel size for reels to other game evaluations using a single lookuptable. In another example, backend-based operation 1700 may not link theexpanded reel size to other game evaluations by using separate RNG callsto lookup tables.

At block 1708, backend-based operation 1700 randomly determines whichreels will have added substitution symbols. If backend-based operation1700 executes the add-substitution symbol feature within a single gameinstance, backend-based operation 1700 may account for a designatedminimum number of reels that will have at least one substitution symboladded to the reels. As an example, the lookup table to determine whichreel will have added substitution symbols could be constructed to add atleast one substitution symbol to two or more reels. If backend-basedoperation 1700 executes the add-substitution symbol feature spin overmultiple game instance, backend-based operation 1700 may not utilize adesignated minimum number of reels.

At block 1710, as part of the reel growth, substitution determinationoperation, backend-based operation 1700 randomly determines whether thesubstitution symbol types for substitution symbols added to each reelare plain-substitution symbols, credit-substitution symbols, and/orother types of substitution symbols. In one or more implementations,backend-based operation 1700 assigns a single substitution type forreels that will receive added substitution symbols. Backend-basedoperation 1700 then moves to block 1712 to randomly determine whichsymbol window positions will receive symbol window position.

At block 1712, in one or more implementations, backend-based operation1700 indirectly determines the number of substitution symbols to add toa given reel by determining whether each symbol window position shouldreceive substitution symbol. For an expanded reel area of 5×8,backend-based operation 1700 executes eight different RNG pulls whereeach RNG pull is for a different symbol window position in a given reel(e.g., reel in column 1). Game processing backend system 314 performseight different RNG pulls because the reel configuration includes eightrows. Each RNG pull randomly determines whether to add a substitutionsymbol to a specific symbol window position. In another implementation,backend-based operation 1700 can first directly determine the number ofsubstitution symbols to add to a reel, which is discussed in more detailwith reference to FIG. 10 .

At block 1714, backend-based operation 1700 performs one or more payoutoperations that include credit-substitution symbols as part of the win.To support the different payout animations for a givencredit-substitution symbol, backend-based operation 1700 performsmultiple payout operations when a credit-substitution symbol substitutesfor another symbol type to form a payline. After determining that acredit-substitution symbol is part of a payline, backend-based operation1700 performs a payout operation using a pay table to determine thepayout amount for the payline. Using FIG. 3 as an example, one of thelookup tables 322 could be a pay table that determines payout for avariety of paylines for a game. In another payout operation,backend-based operation 1700 determines the credit value of thecredit-substitution symbol that is part of the payline. The credit valueof the credit-substitution symbol represents the payout amount for thepayline in the second payout operation. In one or more implementations,backend-based operation 1700 can check whether the total payout amountexceeds a threshold payout amount that is based on a variety of gameparameters, such as bet level and/or bet multiplier. For example, ifbackend-based operation 1700 executes the add-substitution symbolsupplemental feature within a single spin, backend-based operation 1700may perform this check. Alternatively, if backend-based operation 1700executes the add-substitution symbol supplemental feature over multiplespins, backend-based operation 1700 may not perform this check orperform the check with a lower threshold payout amount than the singlespin version of the add-substitution symbol supplemental feature.

Alternatives and Variations

Numerous embodiments are described in this disclosure and are presentedfor illustrative purposes only. The described embodiments are not, andare not intended to be, limiting in any sense. As an example, althoughthe disclosure generally describes the credit-substitution symbolmechanics in a Class III reel or slot game context the disclosure is notlimited to this type of game and/or gaming device. For example, otherimplementations and/or portions of the credit-substitution symbolmechanics may be implemented as a Class II gaming device. In particular,a gaming device may present game play UIs and bonus game UIs whileimplementing a Class II bingo game. Additionally, or alternatively,portions of the credit-substitution symbol mechanics can be utilized forother types of wagering game, such as keno, lottery, and pachinko.

The present disclosure is widely applicable to numerous embodiments, asis readily apparent from the disclosure. One of ordinary skill in theart will recognize that the innovations described herein may bepracticed with various modifications and alterations, such asstructural, logical, software, and electrical modifications. Althoughparticular features of the innovations described herein may be describedwith reference to one or more particular embodiments and/or drawings, itshould be understood that such features are not limited to usage in theone or more particular embodiments or drawings with reference to whichthey are described, unless expressly specified otherwise.

The present disclosure is neither a literal description of allembodiments nor a listing of features of the innovations describedherein that must be present in all embodiments.

The Title (set forth at the beginning of the first page of thisdisclosure) is not to be taken as limiting in any way as the scope ofthe disclosed embodiments. Headings of sections provided in thisdisclosure are for convenience only and are not to be taken as limitingthe disclosure in any way.

When an ordinal number (such as “first,” “second,” “third” and so on) isused as an adjective before a term, that ordinal number is used (unlessexpressly specified otherwise) merely to indicate a particular feature,such as to distinguish that particular feature from another feature thatis described by the same term or by a similar term. For example, a“first widget” may be so named merely to distinguish it from, e.g., a“second widget.” Thus, the mere usage of the ordinal numbers “first” and“second” before the term “widget” does not indicate any otherrelationship between the two widgets, and likewise does not indicate anyother characteristics of either or both widgets. For example, the mereusage of the ordinal numbers “first” and “second” before the term“widget” (1) does not indicate that either widget comes before or afterany other in order or location; (2) does not indicate that either widgetoccurs or acts before or after any other in time; and (3) does notindicate that either widget ranks above or below any other, as inimportance or quality. In addition, the mere usage of ordinal numbersdoes not define a numerical limit to the features identified with theordinal numbers. For example, the mere usage of the ordinal numbers“first” and “second” before the term “widget” does not indicate thatthere must be no more than two widgets.

When introducing elements of aspects of the present disclosure orembodiments thereof, the articles “a,” “an,” “the,” and “said” areintended to mean that there are one or more of the elements. The terms“comprising,” including,” and “having” are intended to be inclusive andmean that there may be additional elements other than the listedelements.

When a single device, component, structure, or article is describedherein, more than one device, component, structure or article (whetheror not they cooperate) may alternatively be used in place of the singledevice, component or article that is described. Accordingly, thefunctionality that is described as being possessed by a device mayalternatively be possessed by more than one device, component or article(whether or not they cooperate).

Similarly, where more than one device, component, structure, or articleis described herein (whether or not they cooperate), a single device,component, structure, or article may alternatively be used in place ofthe more than one device, component, structure, or article that isdescribed. For example, a plurality of computer-based devices may besubstituted with a single computer-based device. Accordingly, thevarious functionality that is described as being possessed by more thanone device, component, structure, or article may alternatively bepossessed by a single device, component, structure, or article.

The functionality and/or the features of a single device that isdescribed may be alternatively embodied by one or more other devicesthat are described but are not explicitly described as having suchfunctionality and/or features. Thus, other embodiments need not includethe described device itself, but rather can include the one or moreother devices which would, in those other embodiments, have suchfunctionality/features.

Further, the systems and methods described herein are not limited to thespecific embodiments described herein but, rather, operations of themethods and/or components of the system and/or apparatus may be utilizedindependently and separately from other operations and/or componentsdescribed herein. Further, the described operations and/or componentsmay also be defined in, or used in combination with, other systems,methods, and/or apparatus, and are not limited to practice with only thesystems, methods, and storage media as described herein.

Devices that are in communication with each other need not be incontinuous communication with each other, unless expressly specifiedotherwise. On the contrary, such devices need only transmit to eachother as necessary or desirable and may actually refrain from exchangingdata most of the time. For example, a machine in communication withanother machine via the Internet may not transmit data to the othermachine for weeks at a time. In addition, devices that are incommunication with each other may communicate directly or indirectlythrough one or more intermediaries.

A description of an embodiment with several components or features doesnot imply that all or even any of such components and/or features arerequired. On the contrary, a variety of optional components aredescribed to illustrate the wide variety of possible embodiments of theinnovations described herein. Unless otherwise specified explicitly, nocomponent and/or feature is essential or required.

Further, although process steps, algorithms or the like may be describedin a sequential order, such processes may be configured to work indifferent orders. In other words, any sequence or order of steps thatmay be explicitly described does not necessarily indicate a requirementthat the steps be performed in that order. The steps of processesdescribed herein may be performed in any order practical. Further, somesteps may be performed simultaneously despite being described or impliedas occurring non-simultaneously (e.g., because one step is describedafter the other step). Moreover, the illustration of a process by itsdepiction in a drawing does not imply that the illustrated process isexclusive of other variations and modifications thereto, does not implythat the illustrated process or any of its steps are necessary to theinnovations described herein, and does not imply that the illustratedprocess is preferred.

Although a process may be described as including a plurality of steps,that does not indicate that all or even any of the steps are essentialor required. Various other embodiments within the scope of the presentdisclosure include other processes that omit some or all of thedescribed steps. Unless otherwise specified explicitly, no step isessential or required.

Although a product may be described as including a plurality ofcomponents, aspects, qualities, characteristics and/or features, thatdoes not indicate that all of the plurality are essential or required.Various other embodiments within the scope of the present disclosureinclude other products that omit some or all of the described plurality.

An enumerated list of items (which may or may not be numbered) does notimply that any or all of the items are mutually exclusive, unlessexpressly specified otherwise. Likewise, an enumerated list of items(which may or may not be numbered) does not imply that any or all of theitems are comprehensive of any category, unless expressly specifiedotherwise.

For the sake of presentation, the detailed description uses terms like“determine” and “select” to describe computer operations in a computersystem. These terms denote operations performed by a computer and shouldnot be confused with acts performed by a human being. The actualcomputer operations corresponding to these terms vary depending onimplementation. For example, “determining” something can be performed ina variety of manners, and therefore the term “determining” (and liketerms) can indicate calculating, computing, deriving, looking up (e.g.,in a table, database or data structure), ascertaining, recognizing, andthe like.

As used herein, the term “send” denotes any way of conveying informationfrom one component to another component, and the term “receive” denotesany way of getting information at one component from another component.The two components can be part of the same computer system or differentcomputer systems. The information can be passed by value (e.g., as aparameter of a message or function call) or passed by reference (e.g.,in a buffer). Depending on context, the information can be communicateddirectly between the two components or be conveyed through one or moreintermediate components. As used herein, the term “connected” denotes anoperable communication link between two components, which can be part ofthe same computer system or different computer systems. The operablecommunication link can be a wired or wireless network connection, whichcan be direct or pass through one or more intermediate components (e.g.,of a network). Communication among computers and devices may beencrypted to ensure privacy and prevent fraud in any of a variety ofways well known in the art.

It will be readily apparent that the various methods and algorithmsdescribed herein may be implemented by, e.g., appropriately programmedgeneral-purpose computers and computing devices. Typically, a processor(e.g., one or more microprocessors) will receive instructions from amemory or like device, and execute those instructions, therebyperforming one or more processes defined by those instructions. Further,programs that implement such methods and algorithms may be stored andtransmitted using a variety of media (e.g., computer readable media) ina number of manners. In some embodiments, hard-wired circuitry or customhardware may be used in place of, or in combination with, softwareinstructions for implementation of the processes of various embodiments.Thus, embodiments are not limited to any specific combination ofhardware and software. Accordingly, a description of a process likewisedescribes at least one apparatus for performing the process, andlikewise describes at least one computer-readable medium for performingthe process. The apparatus that performs the process can includecomponents and devices (e.g., a processor, input and output devices)appropriate to perform the process. A computer-readable medium can storeprogram elements appropriate to perform the method.

The term “computer-readable medium” refers to any non-transitory storageor memory that may store computer-executable instructions or other datain a computer system and be read by a processor in the computer system.A computer-readable medium may take many forms, including but notlimited to non-volatile storage or memory (such as optical or magneticdisk media, a solid-state drive, a flash drive, PROM, EPROM, and otherpersistent memory) and volatile memory (such as DRAM). The term“computer-readable media” excludes signals, waves, and wave forms orother intangible or transitory media that may nevertheless be readableby a computer.

The present disclosure provides, to one of ordinary skill in the art, anenabling description of several embodiments and/or innovations. Some ofthese embodiments and/or innovations may not be claimed in the presentapplication but may nevertheless be claimed in one or more continuingapplications that claim the benefit of priority of the presentapplication. Applicants may file additional applications to pursuepatents for subject matter that has been disclosed and enabled but notclaimed in the present application.

The foregoing description discloses only exemplary embodiments of thepresent disclosure. Modifications of the above disclosed apparatus andmethods which fall within the scope of the present disclosure will bereadily apparent to those of ordinary skill in the art. For example,although the examples discussed above are illustrated for a gamingmarket, embodiments of the present disclosure can be implemented forother markets. The gaming system environment of the examples is notintended to suggest any limitation as to the scope of use orfunctionality of any aspect of the disclosure.

While the invention has been described with respect to the figures, itwill be appreciated that many modifications and changes may be made bythose skilled in the art without departing from the spirit of theinvention. Any variation and derivation from the above description andfigures are included in the scope of the present invention as defined bythe claims. In view of the many possible embodiments to which theprinciples of the disclosed invention may be applied, it should berecognized that the illustrated embodiments are only preferred examplesof the invention and should not be taken as limiting the scope of theinvention. Rather, the scope of the invention is defined by thefollowing claims. We therefore claim as our invention all that comeswithin the scope and spirit of these claims.

What is claimed is:
 1. A non-transitory computer-readable medium storingcomputer-executable instructions which, when executed by at least oneprocessor, cause the at least one processor to: randomly trigger, usinga random number generator, an add-substitution symbol feature in a gameinstance with an initial reel area; randomly determine, based on outputfrom the random number generator and triggering of the add-substitutionsymbol feature, an expanded reel size for a plurality of reels to bedisplayed in an expanded reel area, wherein the expanded reel area islarger than the initial reel area; randomly determine, based on theoutput from the random number generator and triggering of theadd-substitution symbol feature, that a substitution symbol is to beadded to a symbol window position associated with a first reel of theplurality of reels; randomly determine, using output from the randomnumber generator, the symbol window position associated with the firstreel and to which the substitution symbol is to be added; randomlydetermine, based on the output from the random number generator, thatthe substitution symbol is a credit-substitution symbol associated witha specified credit value; randomly determine, using output from therandom number generator, that a second credit-substitution symbol is tobe added at a second symbol window position associated with the firstreel, wherein the credit-substitution symbol and the secondcredit-substitution symbol are added based on separate random numbergenerator outcomes and the second credit-substitution symbol isassociated with a second specified credit value; determine that thecredit-substitution symbol is part of a payline, wherein thecredit-substitution symbol substitutes as a different symbol type whenforming the payline; indirectly determine that the number ofcredit-substitution symbols added to symbol window positions associatedwith the first reel based, at least in part, on counting thecredit-substitution symbol and the second credit-substitution symbolsatisfies a corresponding designated minimum number of substitutionsymbols that should be added to the symbol window positions associatedwith the first reel in the expanded reel area; perform a first payoutfor the payline that pays out a payline award; and perform a secondpayout for the payline that pays out an amount that includes thespecified credit value associated with the credit-substitution symboland the second specified credit value associated with the secondcredit-substitution symbol.
 2. The non-transitory computer-readablemedium of claim 1, further storing additional computer-executableinstructions which, when executed by the at least one processor, furthercause the at least one processor to randomly determine, using outputfrom the random number generator, the symbol window position associatedwith the first reel and to which the substitution symbol is to be added.3. The non-transitory computer-readable medium of claim 2, furtherstoring additional computer-executable instructions which, when executedby the at least one processor, further cause the at least one processorto randomly determine, using output from the random number generator,that a second credit-substitution symbol is to be added at a secondsymbol window position associated with the first reel, wherein thecredit-substitution symbol and the second credit-substitution symbol areadded based on separate random number generator outcomes.
 4. Thenon-transitory computer-readable medium of claim 3, wherein the symbolwindow position is located in a portion of the expanded reel area thatdoes not include the initial reel area and the second symbol windowposition is located in the initial reel area.
 5. The non-transitorycomputer-readable medium of claim 3, further storing additionalcomputer-executable instructions which, when executed by the at leastone processor, further cause the at least one processor to indirectlydetermine the number of credit-substitution symbols added to symbolwindow positions associated with the first reel based, at least in part,on counting the credit-substitution symbol and the secondcredit-substitution symbol.
 6. The non-transitory computer-readablemedium of claim 1, wherein the corresponding designated minimum numberof substitution symbols added to the symbol window positions associatedwith the first reel in the expanded reel area varies according to a sizeof the expanded reel area.
 7. The non-transitory computer-readablemedium of claim 1, further storing additional computer-executableinstructions which, when executed by the at least one processor, furthercause the at least one processor to: determine that the number ofcredit-substitution symbols added to the symbol window positionsassociated with a given reel in the expanded reel area does not satisfya corresponding designated minimum number of substitution symbols thatshould be added to symbol window positions associated with the givenreel in the expanded reel area; and randomly redetermine whether thesubstitution symbol should be added to a symbol window positionassociated with the given reel responsive to determining that thedesignated minimum number of substitution symbols were not added to thesymbol positions associated with the given reel in the expanded reelarea.
 8. A system comprising: one or more displays, one or moreprocessors, and one or more memory devices, the one or more memorydevices storing computer-executable instructions which, when executed bythe one or more processors, cause the one or more processors to:randomly trigger, using a random number generator, an add-substitutionsymbol feature in a game instance with an initial reel area displayed onthe one or more displays; randomly determine, based on output from therandom number generator and triggering of the add-substitution symbolfeature, an expanded reel size for a plurality of reels to be displayedin an expanded reel area, wherein the expanded reel area is larger thanthe initial reel area; randomly determine, based on the output from therandom number generator and triggering of the add-substitution symbolfeature, that a substitution symbol is to be added to a symbol windowposition associated with a first reel of the plurality of reels;randomly determine, using output from the random number generator, thesymbol window position associated with the first reel and to which thesubstitution symbol is to be added; randomly determine, based on theoutput from the random number generator, that the substitution symbol isa credit-substitution symbol associated with a specified credit value;randomly determine, using output from the random number generator, thata second credit-substitution symbol is to be added at a second symbolwindow position associated with the first reel, wherein thecredit-substitution symbol and the second credit-substitution symbol areadded based on separate random number generator outcomes and the secondcredit-substitution symbol is associated with a second specified creditvalue; determine that the credit-substitution symbol is part of apayline, wherein the credit-substitution symbol substitutes as adifferent symbol type when forming the payline; indirectly determinethat the number of credit-substitution symbols added to symbol windowpositions associated with the first reel based, at least in part, oncounting the credit-substitution symbol and the secondcredit-substitution symbol satisfies a corresponding designated minimumnumber of substitution symbols that should be added to the symbol windowpositions associated with the first reel in the expanded reel area;perform a first payout for the payline that pays out a payline award;and perform a second payout for the payline that pays out an amount thatincludes the specified credit value associated with thecredit-substitution symbol and the second specified credit valueassociated with the second credit-substitution symbol.
 9. The system ofclaim 8, wherein the one or more memory devices further store additionalcomputer-executable instructions which, when executed by the one or moreprocessors, further cause the one or more processors to: determine anumber of credit-substitution symbols added to symbol window positionsassociated with a given reel; determine whether the number ofcredit-substitution symbols added to the symbol window positionsassociated with the given reel satisfy a corresponding minimum number ofsubstitution symbols that should be added to the symbol window positionsassociated with the given reel; randomly redetermine, responsive todetermining that the number of credit-substitution symbols added to thesymbol window positions associated with the given reel does not satisfya corresponding minimum number of substitution symbols that should beadded to the symbol window positions associated with the given reel,whether a substitution symbol should be added to another symbol windowposition associated with the given reel.
 10. The system of claim 9,wherein the one or more memory devices further store additionalcomputer-executable instructions which, when executed by the one or moreprocessors, further cause the one or more processors to determine theminimum number of substitution symbols that should be added to thesymbol window positions associated with the given reel based on a sizeof the expanded reel area.
 11. The system of claim 8, wherein the one ormore memory devices further store additional computer-executableinstructions which, when executed by the one or more processors, furthercause the one or more processors to randomly determine, using outputfrom the random number generator, the symbol window position associatedwith the first reel and to which the substitution symbol is to be added.12. The system of claim 11, wherein the one or more memory devicesfurther store additional computer-executable instructions which, whenexecuted by the one or more processors, further cause the one or moreprocessors to randomly determine, using output from the random numbergenerator, that a second credit-substitution symbol is to be added at asecond symbol window position associated with the first reel, whereinthe credit-substitution symbol and the second credit-substitution symbolare added based on separate random number generator outcomes.
 13. Thesystem of claim 12, wherein the symbol window position is located in aportion of the expanded reel area that does not include the initial reelarea and the second symbol window position is located in the initialreel area.
 14. The system of claim 12, wherein the one or more memorydevices further store additional computer-executable instructions which,when executed by the one or more processors, further cause the one ormore processors to indirectly determine the number ofcredit-substitution symbols added to symbol window positions associatedwith the first reel based, at least in part, on counting thecredit-substitution symbol and the second credit-substitution symbol.15. A method comprising: randomly triggering, using a random numbergenerator and by one or more processors, an add-substitution symbolfeature in a game instance with an initial reel area; randomlydetermining, based on output from the random number generator,triggering of the add-substitution symbol feature, and by the one ormore processors, an expanded reel size for a plurality of reels to bedisplayed in an expanded reel area, wherein the expanded reel area islarger than the initial reel area; randomly determining, based on theoutput from the random number generator, triggering of theadd-substitution symbol feature, and by the one or more processors, thata substitution symbol is to be added to a symbol window positionassociated with a first reel of the plurality of reels; randomlydetermining, using output from the random number generator and by theone or more processors, the symbol window position associated with thefirst reel and to which the substitution symbol is to be added; randomlydetermining, based on the output from the random number generator and bythe one or more processors, that the substitution symbol is acredit-substitution symbol associated with a specified credit value;randomly determining, using output from the random number generator andby the one or more processors, that a second credit-substitution symbolis to be added at a second symbol window position associated with thefirst reel, wherein the credit-substitution symbol and the secondcredit-substitution symbol are added based on separate random numbergenerator outcomes and the second credit-substitution symbol isassociated with a second specified credit value; determining, by the oneor more processors, that the credit-substitution symbol is part of apayline, wherein the credit-substitution symbol substitutes as adifferent symbol type when forming the payline; indirectly determining,by the one or more processors, that the number of credit-substitutionsymbols added to symbol window positions associated with the first reelbased, at least in part, on counting the credit-substitution symbol andthe second credit-substitution symbol satisfies a correspondingdesignated minimum number of substitution symbols that should be addedto the symbol window positions associated with the first reel in theexpanded reel area; causing, by the one or more processors, a firstpayout for the payline that pays out a payline award to be performed;and causing, by the one or more processors, a second payout for thepayline that pays out an amount that includes the specified credit valueassociated with the credit-substitution symbol and the second specifiedcredit value associated with the second credit-substitution symbol to beperformed.
 16. The method of claim 15, wherein the correspondingdesignated minimum number of substitution symbols added to the symbolwindow positions associated with the first reel in the expanded reelarea varies according to a size of the expanded reel area.
 17. Themethod of claim 15, further comprising: determining, by the one or moreprocessors, that the number of credit-substitution symbols added to thesymbol window positions associated with a given reel in the expandedreel area does not satisfy a corresponding designated minimum number ofsubstitution symbols that should be added to symbol window positionsassociated with the given reel in the expanded reel area; and randomlyredetermining, by the one or more processors, whether the substitutionsymbol should be added to a symbol window position associated with thegiven reel responsive to determining that the designated minimum numberof substitution symbols were not added to the symbol positionsassociated with the given reel in the expanded reel area.
 18. The methodof claim 15, further comprising randomly determining, using output fromthe random number generator and by the one or more processors, thesymbol window position associated with the first reel and to which thesubstitution symbol is to be added.
 19. The method of claim 18, furthercomprising randomly determining, using output from the random numbergenerator and by the one or more processors, that a secondcredit-substitution symbol is to be added at a second symbol windowposition associated with the first reel, wherein the credit-substitutionsymbol and the second credit-substitution symbol are added based onseparate random number generator outcomes.
 20. The method of claim 19,wherein the symbol window position is located in a portion of theexpanded reel area that does not include the initial reel area and thesecond symbol window position is located in the initial reel area.